In humans, coital vocalizations are linked to sexual pleasure or sexual gratification and  orgasm , [ 8 ]  hence occurring during  copulation  and serving as an expression of  sexual pleasure . Vocalizations can be used intentionally by women in order to boost the  self-esteem  of their  partner  and to cause quicker  ejaculation . [ 9 ]


In addition to emitting copulatory vocalizations during and after copulation (as it is mostly seen in primates), non-primate species also vocalize before engaging in mating. Vocalizations that are made prior to copulation are named  mating calls . They serve as a means to advertise sexual receptivity and are predominantly used by males to attract female mates. [ 10 ]  In general, non-primates emit more calls before copulating, as exemplified by the  croaks  of male frogs [ 11 ]  and the melodic tweeting of  song sparrows . [ 12 ]


In regard to the calling properties, frequency analysis is typically used in research to look at the complexity of the vocalization and to distinguish between calls, which is important in determining their function. [ 13 ]  Large frequency variations have been noted between species, ranging from 14 Hz to 70,000 Hz.  Mice , for instance, use 70,000 Hz calls continuously prior to copulation. They then lower the frequency down to 40,000 Hz during the copulatory act, therefore two qualitatively different calls are used for attracting mates as compared to the actual act of mating. [ 5 ]  Most of the calling in mice is done by males. They use these  ultrasonic  calls (> 20,000 Hz and hence not discernible by the human ear) to attract females, with the quantity of calls being related to the male's mating success, making these vocalizations a  sexually selected  trait. [ 14 ]


On the other end of the spectrum, female  African elephants  use very low frequency calls of 14–35 Hz prior to, as well as during, copulation. [ 4 ]  Due to their low frequency these calls can be heard for several kilometers and are therefore effective in signalling receptivity. The vocalizations of female elephants are also used in order to incite  mate guarding  behavior in the male, [ 6 ]  which manifests itself in the form of fighting off any newly arriving mates. Not only females make use of this, as male  Columbian ground squirrels  have been observed to use copulatory vocalizations in order to announce their post-copulatory mate guarding to others. [ 15 ]  In addition to being used to retain the mate via mate guarding induction, female copulatory vocalizations can also be employed to achieve his departure.  Red junglefowls , for instance, utilize calls in order to prevent or end unwanted copulations by attracting another high-ranking male fowl. [ 7 ]  Further effects of female calling on male's behavior are illustrated by  spiders  that have been shown to  stridulate  before copulation to inform males of sexual receptivity [ 16 ]  as well as  during intercourse in order to influence male genitalic movements. [ 17 ]


Moreover, attracting new mates by calling out during copulation can entail many benefits for the female. Female  crickets  which mate with multiple partners receive a greater number of  nuptial gifts , [ 18 ]  causing them to lay a larger quantity of eggs, hence increasing their  reproductive success .


In non-human primates, copulatory vocalizations begin towards the end of the copulatory act or even after copulation. [ 2 ]  The percentage of vocalizations after copulation varies dependent on the non-human primate species studied. In long-tail macaques, for instance, 80% of copulations are followed by  copulation  calls. In contrast, the percentage for  chimpanzees  and  Tonkean macaques  has been found to be 78.8% and 6%, respectively. [ 20 ]  There is little consensus on what causes these inter-specific differences, given the lack of consistent findings within the literature. [ 2 ]  The typical quantity of specimen that are tested in  experimental settings  is often too low in order to allow any  general conclusions  about the species as a whole. [ 2 ]


Another aspect of coital vocalization that varies according to species is the form of the call: in  macaques  and  baboons  they manifest themselves as  grunts , whereas other species such as  talapoins  and  chimpanzees  typically emit  screaming  sounds. [ 2 ]  The quality and structure of copulatory calls are analyzed by comparing their respective  spectrograms  in terms of their frequency. Accordingly, some species produce calls that are structurally more complex than that of others. This is linked to the amount of  promiscuity  exhibited, in a way that more promiscuous species emit more faceted calls in order to convey more information about themselves and hence render  self-advertisement  more efficient. [ 19 ]


Copulatory calls in primates serve an  adaptive function  and are  sexually selected . [ 3 ]  Calling signals sexual receptivity of the female and therefore affects  mate choice . There are many different hypotheses as to the exact adaptive function of female copulatory calls in primates and research on the subject is still in its early stages. [ 2 ]


There is general agreement that copulatory calls are the adaptive solution to problems with  reproductive success . In other words, copulatory vocalizations address issues that stand in the way of successfully producing  offspring  and guaranteeing its survival, such as the occurrence of infanticide. [ 21 ]  To prevent the killing of their offspring, female baboons employ copulatory calls in order to attract other males, allowing multiple mating acts and creating parental confusion among the males involved. The resulting uncertainty of who the father is hence reduces the occurrence of attacks, given the newly incited risk of potentially harming their own offspring. [ 22 ]  Additionally, mating in rapid successions also entails sperm competition, and therefore fulfills the additional function of obtaining high quality sperm. [ 23 ]  This is especially important in species that do not openly advertise good genes via  honest signals . [ 24 ]


By attracting other males through post-copulatory calls, the female might provoke mate guarding behavior in their initial mate. This 'parental concentration', [ 2 ]  has two outcomes. Firstly, the male might be of high  quality , allowing him to fend off those that were attracted by the call. In that case the female has not only gained someone who can protect her and who prevents infanticide through other males, but this also means that she was  inseminated  by a specimen with potentially good genes. Secondly, if the male fails to successfully guard her, she will mate with the newly arrived males, hence inciting sperm competition and paternity confusion (again preventing  attacks on her offspring , as well as increasing her likelihood of obtaining high quality sperm). The calls produced by the female also carry information about the  status  of the male with whom she was copulating, thus allowing her to influence the likelihood of other males approaching. [ 8 ]


Accordingly, copulatory calls serve more than a single adaptive function. There is no  mutual exclusivity  when it comes to addressing the two problems described, namely that of infanticide and receiving high quality sperm. However, by taking the female's  cycle stage  into account, sperm competition can be ruled out as the primary underlying cause of copulatory calling. [ 25 ]  More precisely, females produce coital vocalizations also when they mate during non-fertile periods, which is therefore primarily aimed at attracting as many males as possible and to create parental confusion rather than obtaining high quality sperm. [ 26 ]  Females have no interest in advertising their periods of  fertility , given that males would pick up on these patterns, reducing paternal confusion and causing an increase in  aggressive behavior towards her offspring  from other males. [ 2 ]  Such hidden fertility has been coined  concealed ovulation , and is part of  extended female sexuality .


In addition to the incitement of parental confusion in order to avoid infanticide, female primates that exhibit  promiscuous behavior  also reap non-genetic material benefits. A female that uses vocalizations after copulating with her mate attracts other males, with whom she is also likely to engage in multiple acts of mating. [ 19 ]  As a consequence male mates provide non-genetic benefits, such as food, to the female they mated with. [ 27 ]  Such vocalization-facilitated promiscuity heightens the female's  reproductive success . The strategy to mate with multiple partners in order to obtain material benefits can equally be observed in non-primates. [ 28 ]


Theories are more diverse in regard to women's sexual vocalizing.


On one hand, researchers have noted some apparently communicative patterns in women’s copulatory vocalizations that suggest some parallels with those of other primates (including an invitation to sperm competition, given that female sexual vocalizations, like those of other primates, serve as "copulation calls" noticeable to other men and exciting to them if overheard [ 8 ] ). One study, for instance, has noted that female sexual vocalizations tend to become more intense as she approaches orgasm. At orgasm her vocalizations are usually discrete and are not random, appearing related to observed contractions of the superficial perivaginal striated muscles; these in turn probably correlate with each wave of erotic pleasure. [ 29 ]  The vocalization tends to become very rapid, with a regular rhythm that includes equal note lengths and intervals between notes, which male vocalization typically lacks. [ 19 ]  This is especially frequent when her orgasm occurs during  penile-vaginal intercourse . [ 9 ]  By exciting her partner with her vocalizations and bringing about his orgasm at that point, she helps ensure that the  seminal pool  is available for her  cervix  to dip into as her  vagina  relaxes after her orgasm. [ 19 ]  Copulatory vocalizations may also be a type of mate retention behaviour. One study found that women who perceived a high risk of  infidelity  in their relationship were more likely to utilize copulatory vocalizations in order to  fake an orgasm , along with other mate-retention behaviours. [ 30 ]


On the other hand, a recent study has indicated that most copulatory vocalizations in women do not accompany their own orgasm, but rather their partner's ejaculation. The study showed that the man typically finds the woman's vocalization arousing and highly exciting, and that the woman herself is aware of this. Most women in the study, furthermore, indicated that they vocalized during intercourse to make their man ejaculate more quickly, or to boost his enjoyment or  self-esteem , or both. [ 9 ]  A correlation has been found between the frequency of vocalizations and sexual satisfaction for both men and women. [ 31 ]


The reasons that women gave for wanting to force a quick ejaculation include the alleviation of the female's pain, fatigue, or even boredom, or simply to stay within some imposed time restriction for sexual activity. Reasons for wanting to boost the male self-esteem included reinforcing the  pair bond  that intercourse helps to strengthen, and thus reducing emotional and sexual infidelity and abandonment. [ 9 ]  The researchers note that all of these goals are apparently congruent with female copulatory vocalizations in non-human primates.


Female sexual arousal disorder  ( FSAD ) is a disorder characterized by a persistent or recurrent inability to attain  sexual arousal  or to maintain arousal until the completion of a  sexual activity . The diagnosis can also refer to an inadequate  lubrication -swelling response normally present during arousal and sexual activity. The condition should be distinguished from a general loss of interest in sexual activity and from other  sexual dysfunctions , such as the orgasmic disorder ( anorgasmia ) and  hypoactive sexual desire disorder , which is characterized as a lack or absence of  sexual fantasies  and desire for sexual activity for some period of time.


Although female sexual dysfunction is currently a contested diagnostic, it has become more common in recent years to use  testosterone -based drugs off-label to treat FSAD. It is a subtype of female sexual dysfunction. It occurs in distress due to the inability to attain or maintain adequate vaginal lubrication.


There are three types of FSAD which have been identified: genital arousal disorder, subjective arousal disorder, and combined arousal disorder.


With genital arousal disorder, there is still a mental feeling of arousal, but it is not matched by any physical response. For example, a woman may be "turned on" by her partner, but her vagina does not produce lubrication and there is little-to-no increase in blood flow to the genitals. Subjective arousal disorder is the reverse issue, where there is a physical response to sexual circumstances, but an inability to feel mentally aroused. Combined arousal disorder combines both genital arousal disorder and subjective arousal disorder, presenting as a lack of sexual feeling altogether, both mentally and physically. [ 2 ]


A number of studies have explored the factors that contribute to female sexual arousal disorder and female orgasmic disorder. These factors include both psychological and physical factors.


There has been little investigation of the impact of individual factors on female sexual dysfunction. Such factors include stress, levels of fatigue,  gender identity , health, and other individual attributes and experiences, such as dysfunctional sexual beliefs [ 3 ]  that may affect sexual desire or response. An individual's sexual activity is disrupted by overwhelming emotional distress resulting in inability to attain sexual pleasure. Sexual dysfunction can also occur secondary to major psychiatric disorders, including  depression . [ 4 ]


A substantial body of research has explored the role of interpersonal factors in female sexual dysfunction, particularly in relation to orgasmic response. These studies have largely focused on the impact of the quality of the relationship on the sexual functioning of the partners. Some studies have evaluated the role of specific relationship variables, whereas others have examined overall relationship satisfaction. [ 5 ]  Some studies have explored events, while others have focused on attitudes as an empirical measure of relationship functioning. Subject populations have varied from distressed couples to sexually dysfunctional clients to those in satisfied relationships.


Estimates of the percentage of female sexual dysfunction attributable to physical factors have ranged from 30% to 80%. The disorders most likely to result in sexual dysfunction are those that lead to problems in circulatory or neurological function. These factors have been more extensively explored in men than in women. Physical etiologies such as neurological and cardiovascular illnesses have been directly implicated in both premature and retarded ejaculation as well as in erectile disorder, [ 6 ]  but the contribution of physiological factors to female sexual dysfunction is not so clear. However, recent literature does suggest that there may be an impairment in the arousal phase among diabetic women. Given that diabetic women show a significant variability in their response to this medical disorder, it is not surprising that the disease's influence on arousal is also highly variable. In fact, the lack of a clear association between medical disorders and sexual functioning suggests that psychological factors play a significant part in the impact of these disorders on sexual functioning. [ 7 ]


Several types of medications, including  selective serotonin reuptake inhibitors  (SSRIs), can cause sexual dysfunction and in the case of SSRI and SNRI, these dysfunctions may become permanent after the end of the treatment. [ 4 ]


One third of  post operation   transgender women  experience FSAD roughly consistent with  menopause  women. HSDD in transgender women is largely caused by a lack of testosterone especially after the  gonads  are removed during  bottom surgery , as  androgens  are produced in smaller concentrations lower than  ovulating  women.  Progesterone  has shown to alleviate some symptoms of HSDD in transgender women, as well as other  hormone treatments . [ 8 ] [ 9 ]


Kaplan [ clarification needed ]  proposed that sexual dysfunction was based on intrapsychic, interpersonal, and behavioural levels. [ 4 ] [ page needed ]  Four factors were identified that could have a role in the development of sexual dysfunction: 1) lack of correct information regarding sexual and social interaction, 2) unconscious  guilt  or  anxiety  regarding sex, 3)  performance anxiety , and 4) failure to communicate between the partners. [ 4 ] [ page needed ]


The  DSM-5  lists the diagnostic criteria as including a minimum of three of the following: [ 10 ]


The  DSM-IV  (American Psychiatric Association 1994) diagnostic criteria were:


Marita P. McCabe noted:


Difficulties arise with this definition in terms of what constitutes an adequate lubrication-swelling response. There is no "gold standard" regarding the length of time it should take to become aroused or the level of arousal that should be achieved. These responses may vary from one woman to another and are dependent on a range of factors, which include her general mood when sexual stimulation commences and her partner's skill in stimulating her. There may also be differences in physiological and subjective levels of arousal, with some women reporting no feelings of sexual arousal despite evidence of vaginal vasocongestion and others reporting arousal in the absence of such evidence. The expectations and past experiences of clinicians and clients may also lead them to classify the same symptoms as female sexual arousal disorder in one woman but not in another. [ 12 ]


There are several subtypes of female sexual arousal disorders. They may indicate onset: lifelong (since birth) or acquired. They may be based on context: they may occur in all situations (generalized) or be situation-specific (situational). For example, the disorder may occur with a spouse but not with a different partner.


The length of time the disorder has existed and the extent to which it is partner- or situation-specific, as opposed to occurring in all situations, may be the result of different causative factors and may influence the treatment for the disorder. It may be due to psychological factors or a combination of factors.


The FDA has approved  flibanserin [ 13 ]  and  bremelanotide [ 14 ]  for low sexual libido in women.


One problem with the current definition in the DSM-IV  [ 15 ]  is that subjective arousal is not included. There is often no correlation between women's subjective and physiological arousal. [ 16 ]  With this in mind, recently, FSAD has been divided up into sub-types:


The third sub-type is the most common in clinical settings. [ 17 ]


One criticism is that "the meaningful benefits of experimental drugs for women's sexual difficulties are questionable, and the financial conflicts of interest of experts who endorse the notion of a highly prevalent medical condition are extensive." [ 18 ]


Professor of bioethics and sociology Jennifer R. Fishman argues that the categorization of female sexual dysfunction as a treatable disease has only been made possible through the input of academic clinical researchers. Through ethnographic research, she believes she has shown how academic clinical researchers have provided the scientific research needed by pharmaceutical companies to bio-medicalize female sexual dysfunction and consequently identify a market of consumers for it. She questions the professional ethics of this exchange network between researchers and pharmaceutical companies, as the clinical research trials are funded by pharmaceutical companies and researchers are given considerable financial rewards for their work. She argues that the conferences where definition of the disease and diagnostic criteria are defined and research is presented to clinicians are also ethically ambiguous, as they are also funded by pharmaceutical companies. [ 19 ]


Heather Hartely of Portland State University, Oregon is critical of the shift from female sexual dysfunction being framed as an arousal problem to a desire problem. In her article, "The 'Pinking' of Viagra Culture", she states that the change from hypoactive sexual desire disorder to female sexual arousal disorder is indicative of "disease mongering" tactics by the drug industry through an effort to match up a drug to some subcomponent of the DSM classification. [ 20 ]


Additionally,  Leonore Tiefer  of NYU School of Medicine voiced concerns that the success of Viagra, in combination with feminist rhetoric, were being used as a means of fast-tracking public acceptance of pharmaceutical treatment of female sexual arousal disorder. The justification behind this, she says, is that "the branding of Viagra has succeeded so thoroughly in rationalizing the idea of sexual correction and enhancement through pills that it seems inevitable and  only fair  that such a product be made available for women," giving a dangerous appeal to "nonapproved drugs though off-label prescribing". [ 21 ]


Behavioral Treatments İn Female Sexual Dysfunctions


Flushing  is to become markedly  red  in the  face  and often other areas of the skin, from various  physiological  conditions. Flushing is generally distinguished  from  blushing , since blushing is psychosomatic, milder, generally restricted to the face, cheeks or ears, and generally assumed to reflect emotional  stress , such as  embarrassment ,  anger , or  romantic stimulation . Flushing is also a cardinal symptom of  carcinoid syndrome —the syndrome that results from  hormones  (often  serotonin  or  histamine ) being  secreted  into  systemic circulation .


Commonly referred to as the sex flush,  vasocongestion  (increased  blood  flow) of the  skin  can occur during all four phases of the  human sexual response cycle . Studies show that the sex flush occurs in approximately 50–75% of  females  and 25% of  males , yet not consistently. [ citation needed ]  The sex flush tends to occur more often under warmer conditions and may not appear at all under lower  temperatures . [ citation needed ]


During the female sex flush,  pinkish  spots develop under the  breasts , then spread to the breasts,  torso ,  face ,  hands ,  soles  of the  feet , and possibly over the entire  body . Vasocongestion is also responsible for the darkening of the  clitoris  and the walls of the  vagina  during  sexual arousal . During the male sex flush, the  coloration  of the skin develops less consistently than in the female, but typically starts with the  epigastrium  (upper  abdomen ), spreads across the  chest , then continues to the  neck ,  face ,  forehead ,  back , and sometimes,  shoulders  and  forearms . [ citation needed ]


The sex flush typically disappears soon after reaching  orgasm , but in other cases, may take up to two hours or more, and sometimes intense  sweating  occurs simultaneously. [ citation needed ]


In  male   human anatomy , the  foreskin , also known as the  prepuce  ( / ˈ p r iː p juː s / ), is the double-layered fold of  skin ,  mucosal  and  muscular  tissue at the distal end of the  human penis  that covers the  glans  and the  urinary meatus . [ 2 ]  The foreskin is attached to the glans by an elastic band of tissue, known as the  frenulum . [ 3 ]  The outer skin of the foreskin meets with the inner  preputial mucosa  at the area of the  mucocutaneous junction . [ 4 ]  The foreskin is mobile, fairly stretchable and sustains the glans in a moist environment. [ 5 ]  Except for humans, a similar structure known as a  penile sheath  appears in the male  sexual organs  of all  primates  and the vast majority of  mammals . [ 6 ]


In humans, foreskin length varies widely and coverage of the glans in a flaccid and erect state can also vary. [ 7 ]  The foreskin is fused to the glans at birth and is generally not  retractable  in infancy and early childhood. [ 8 ]  Inability to retract the foreskin in childhood should not be considered a problem unless there are other symptoms. [ 9 ]  Retraction of the foreskin is not recommended until it loosens from the glans before or during puberty. [ 9 ]  In adults, it is typically retractable over the glans, given normal development. [ 9 ]  The male prepuce is anatomically  homologous  to the  clitoral hood  in females. [ 10 ] [ 11 ]  In some cases, the foreskin may become subject to a pathological condition. [ a ] [ 12 ]


The outside of the foreskin is a continuation of the  shaft  skin of the penis and is covered by a  keratinized   stratified squamous epithelium . The  inner foreskin  is a continuation of the epithelium that covers the  glans  and is made up of  glabrous  squamous  mucous membrane , like the inside of the eyelid or the  mouth . [ 13 ]  The mucosal aspect of the prepuce has a great capacity for self-repair. [ 14 ]  The area of the outer foreskin measures 7–100 cm 2 , [ 15 ]  and the inner foreskin measures 18–68 cm. 2 [ 7 ]  The  mucocutaneous zone  occurs where the outer and inner foreskin meet. The foreskin is free to move after it separates from the glans, which usually occurs before or during  puberty . The inner foreskin is attached to the glans by the  frenulum , a highly  vascularized  tissue of the penis. [ 16 ]  The  World Health Organization  states that "the frenulum forms the interface between the outer and inner foreskin layers, and when the penis is not erect, it tightens to narrow the foreskin opening. [ 16 ]


The human foreskin is a  laminar  structure made up of  outer skin ,  mucosal epithelium ,  lamina propia ,  dartos fascia  and  dermis . [ 14 ] [ 17 ]  The superficial dartos fascia, formerly called the  peripenic muscle , is one of the two sheaths of  smooth muscle tissue  found below the penile skin, along with the underlying  Buck's fascia  or  deep   fascia of the penis . [ 18 ]  The dartos fascia extents within the skin of the prepuce and contains an abuncance of  elastic fibers . [ 19 ]  These fibers form a whorl at the tip of the foreskin, known as the preputial orifice, which is narrow during infancy and childhood. [ 20 ] [ 17 ]  The dartos fascia is sensitive to temperature and reacts to temperature changes by expanding and contracting. [ 21 ]  The fascia is only loosely connected with the underlying tissue, so that it provides the mobility and elasticity of the penile skin. [ 19 ]   Langerhans cells  are immature dendritic cells that are found in all areas of the penile epithelium, but are most superficial in the inner surface of the foreskin. [ 22 ]


As a continuation of the human shaft skin, the prepuce receives  somatosensory   innervation  from the bilateral  dorsal nerve of the penis  and branches of the  perineal nerve , and  autonomic  innervation from the  pelvic plexus . [ 23 ] [ 24 ]  The somatosensory  receptors  that are found in the prepuce are both  nociceptors  and  mechanoreceptors , with a predominace of  Meissner's corpuscles . [ 23 ] [ 25 ]  Blood supply to the prepuce is provided by the preputial artery, a division of the axial and  dorsal artery of the penis . [ 18 ]  The axial and dorsal arteries that run within the penile skin  unite  through perforating branches and give off the preputial arteries before they reach the  corona of the glans . [ 26 ] [ 27 ]  The preputial vein, an extension of the superficial dorsal vein, receives blood from the prepuce and connects to the larger  dorsal veins of the penis  that drain the rest of the penile shaft. [ 28 ] [ 29 ]


The penis develops from a  primordial phallic  structure that forms in the  embryo  during the early weeks of pregnancy, known as the  genital tubercle . [ 30 ]  Initially undifferentiated, the tubercle develops into a penis depending on the exposure to  male hormones  secreted by the  testicles . [ 31 ]  The  differentiation  of the external sexual organs will be evident between twelve and sixteen weeks of  gestation . [ 32 ] [ 33 ]  Preputial development is initiated at around eleven weeks or earlier and continues up to eighteen weeks. [ 34 ] [ 35 ] [ 36 ]


Historically, the theories regarding the stages of preputial development during gestation fall into two main ideas. [ 37 ]  The earliest report by Schweigger-Seidel (1866) [ 38 ]  and later Hunter (1935) [ 39 ]  suggested the formation of the prepuce out of dorsal skin and its progressive distal extension to completely cover and eventually fuse with the  epithelium  of the glans. [ 37 ]  Glenister (1956) [ 40 ]  expanded the theory suggesting that the preputial fold results as an ingrowth of the  cellular lamina , which rolls outwards over the glans, but with the resultant preputial lamina also expanding backwards to form an ingrowing fold at the coronal sulcus. [ 37 ]


By eleven and twelve weeks of gestation, the process of preputial formation is evident as a thickening of the  epidermis  that separates from the penis creating a raised fold, known as the preputial fold. [ 41 ]  On the underside of this structure forms the preputial lamina, which expands dorsolaterally over the base of the developing glans. [ 42 ] [ 43 ]  At thirteen weeks, the prepuce has not yet extended to the distal tip of the glans covering only a part of its surface. [ 44 ]  By sixteen weeks, the bilateral preputial folds cover most of the glans and the ventral sides of the prepuce fuse in the midline. [ 45 ]  The  penile raphe , the continuation of the  perineal raphe  in human males, occurs on the ventral side of the penis as a manifestation of the fusion of the urethral and preputial folds. [ 46 ]  The dorsal nerve of the penis, which is present as early as nine weeks of gestation, completely expands through branches to the distal end of the glans and prepuce by sixteen weeks. [ 47 ]  At nineteen weeks, foreskin development is complete. [ 35 ]  Towards the end of the second  trimester , [ 48 ]  the glans and the prepuce have completely fused together by the preputial, sometimes referred to as  balanopreputial  lamina. [ 49 ]  At birth, this shared membrane is physiologically adherent to the glans preventing retraction in infancy and early childhood. [ 50 ] [ 51 ]  The phenomenon of non-retractile foreskin in children naturally starts to resolve in varying ages; in childhood, preadolescence or puberty. [ 52 ]


During the first years of life, the inner foreskin is fused to the glans making them hard to manually separate. [ 8 ] [ 53 ]  At that time, forced retraction can cause pain or microtearing and is thus not recommended. [ 54 ] [ 55 ] [ 56 ]  The two surfaces may begin to separate from early childhood, but complete separation and retraction is a process that normally occurs over time. [ 57 ] [ 58 ]  The phenomenon of non retractile or tight foreskin in childhood, sometimes referred to as physiologic phimosis, [ 51 ]  may completely resolve before, during or even after puberty. [ 9 ] [ 59 ] [ 55 ]  When the foreskin starts to become retractile, a pediatrician can recommend careful retraction at home and rinsing with water during bath. [ 54 ]  Mild soap may be used, but can be avoided, if it causes irritation. [ 56 ]  If full retraction is hard to achieve, the child may only wash the exposed area of the glans. [ 60 ]  Since there is no specific age when non-retractile foreskin begins to resolve, the time of foreskin retraction can vary considerably among children. [ 52 ]


During  puberty , as the male begins to  sexually mature , foreskin retractability gradually increases allowing more comfortable exposure of the glans when needed. Gentle washing under the foreskin during shower and maintaining good genital hygiene is sufficient to prevent smegma buildup. [ 61 ] [ 57 ]  Smegma is an oily secretion in the genitals of both  sexes  that maintains the moist texture of the mucosal surfaces and prevents friction. [ 62 ] [ 63 ]  In boys, it helps resolve the natural adhension of the glans and inner prepuce. [ 64 ] [ 53 ]  By the end of puberty, most boys have a fully retractable foreskin. [ 59 ]


In children, the foreskin usually covers the glans completely but in adults it may not. During  erection , the degree of automatic foreskin retraction varies considerably; in some adults, when the foreskin is longer than the erect penis, it will not spontaneously retract upon erection. In this case, the foreskin remains covering all or some of the glans until retracted manually or by  sexual activity . The foreskin can be classified as long, when the preputial orifice extents beyond the glans, medium, when the preputial orifice is located around the meatus, and short, when most of the glans is exposed. [ 65 ]  The variation of long foreskin was regarded by Chengzu (2011) as 'prepuce redundant'. Frequent retraction and washing under the foreskin is suggested for all adults, particularly for those with a long or 'redundant' foreskin. [ 66 ]  Some males, according to Xianze (2012), may be reluctant for their glans to be exposed because of discomfort when it chafes against clothing, although the discomfort on the glans was reported to diminish within one week of continuous exposure. [ 67 ]  Guochang (2010) states that for those whose foreskins are too tight to retract or have some adhesions, forcible retraction should be avoided since it may cause injury. [ 68 ]


The foreskin is part of the human  phylogenetic  heritage and is present in the vast majority of mammals. Non-human  primates , such as the  chimpanzees , have prepuces that partially or completely cover the glans penis. [ 16 ]  In primates, the foreskin is present in the genitalia of both sexes and likely has been present for millions of years of evolution. [ 69 ]


The  World Health Organization  (WHO) stated in 2007 that there was "debate about the role of the foreskin, with possible functions including keeping the glans moist, protecting the developing penis in utero, or enhancing sexual pleasure due to the presence of nerve receptors". [ 16 ]  In 2009, the  World Health Organization  called it a "myth" that  circumcision  has an effect on sexual pleasure. The view is echoed by other  major medical organizations . [ 70 ]  The foreskin contains  Meissner's corpuscles , which are one of a group of nerve endings involved in fine-touch sensitivity. Compared to other hairless skin areas on the body, the Meissner's index was highest in the finger tip (0.96) and lowest in the foreskin (0.28) which suggested that the foreskin has the least sensitive hairless tissue of the body. [ 71 ]  The foreskin helps to provide sufficient skin during an erection. [ 72 ]  In infants, it protects the glans from ammonia and feces in diapers, which reduces the incidence of  meatal stenosis . And the foreskin helps prevent the glans from getting abrasions and trauma throughout life. [ 72 ]


In modern times, there is controversy regarding whether the foreskin is a vital or  vestigial structure . [ 73 ]  In 1949, British physician  Douglas Gairdner  noted that the foreskin plays an important protective role in newborns. He wrote, "It is often stated that the prepuce is a vestigial structure devoid of function... However, it seems to be no accident that during the years when the child is incontinent the glans is completely clothed by the prepuce, for, deprived of this protection, the glans becomes susceptible to injury from contact with sodden clothes or napkin". [ 73 ]  During the physical act of sex, the foreskin reduces friction, which can reduce the need for additional sources of lubrication. [ 73 ]  The  College of Physicians and Surgeons of British Columbia  has written that the foreskin is "composed of an outer skin and an  inner mucosa  that is rich in specialized sensory nerve endings and erogenous tissue". [ 74 ]  In the March 2017 publication of the  Global Health Journal: Science and Practice , Morris and Krieger wrote, "The variability in foreskin size is consistent with the foreskin being a vestigial structure". [ 75 ]


The foreskin can be involved in  balanitis ,  phimosis ,  sexually transmitted infection  and  penile cancer . [ 76 ]  The American Academy of Pediatricians' now expired 2012 technical report on circumcision found that the foreskin can harbor micro-organisms that may increase the risk of urinary tract infections in some infants and contribute to the transmission of some sexually transmitted infections in adults. [ 77 ]  In some cases of recurrent pathologies, excessive soap washing may irritate the mucosa, therefore washing of the area should be done gently. [ 78 ]


Frenulum breve  is a  frenulum  that is insufficiently long to allow the foreskin to fully retract, which may lead to discomfort during intercourse. [ medical citation needed ]


Phimosis  is a condition where the foreskin of an adult cannot be retracted properly. Phimosis can be treated by using topical  steroid  ointments and using lubricants during sex; for severe cases circumcision may be necessary. [ 79 ]   Posthitis  is an inflammation of the foreskin.


A condition called  paraphimosis  may occur if a tight foreskin becomes trapped behind the glans and swells as a restrictive ring. This can cut off the blood supply, resulting in  ischemia  of the glans penis. [ 79 ]


Lichen sclerosus  is a chronic, inflammatory skin condition that most commonly occurs in adult women, although it may also be seen in men and children. Topical  clobetasol propionate  and  mometasone furoate  were proven effective in treating genital lichen sclerosus. [ 80 ]


Some birth defects of the foreskin can occur; all of them are rare. In  aposthia  there is no foreskin at birth, [ 81 ] : 37–39   in micropathia the foreskin does not cover the glans, [ 81 ] : 41–45   and in macroposthia, also called and congenital megaprepuce, the foreskin extends well past the end of the glans. [ 81 ] : 47–50


It has been found that larger foreskins place men who are not circumcised at an increased risk of HIV infection [ 82 ]  most likely due to the larger surface area of inner foreskin and the high concentration of  Langerhans cells . [ 83 ]


Circumcision is the removal of the foreskin, either partially or completely. It is most commonly performed as an elective procedure for  prophylactic ,  cultural , or  religious  reasons. [ 84 ] [ 85 ] : 257   Circumcision may also be performed on children or adults to treat phimosis, balanitis, and other pathologies. [ 86 ]  The  ethics of circumcision  in children is a source of  controversy . [ 87 ] [ 88 ]  Some men  use weights or other devices  to stretch the skin of the penis to regrow a foreskin; the resulting tissue does cover the glans but does not fully replicate the features of a foreskin. [ 89 ]  Other cultural or aesethetic practices include  genital piercings  involving the foreskin and  slitting the foreskin . [ 90 ]   Preputioplasty  is the most common foreskin reconstruction technique, most often done when a boy is born with a foreskin that is too small; [ 91 ] : 177   a similar procedure is performed to relieve a tight foreskin without resorting to circumcision. [ 91 ] : 181


Foreskins obtained from circumcision procedures are frequently used by biochemical and micro-anatomical researchers to study the structure and proteins of human skin. In particular, foreskins obtained from newborns have been found to be useful in the manufacturing of more human skin. [ 92 ]


Foreskins of babies are also used for  skin graft  tissue, [ 93 ] [ 94 ] [ 95 ]  and for  β-interferon -based drugs. [ 96 ]


Foreskin-derived  fibroblasts  have been used in biomedical research, [ 97 ]  and cosmetic applications. [ 98 ]


The foreskin was considered a sign of  beauty ,  civility , and  masculinity  throughout the  Greco-Roman world . [ 99 ]  In  ancient Greece , foreskins were valued, especially those that were longer. [ 100 ]  The earliest known illustrative depiction of the foreskin dates back to  Egyptian kingdoms . [ 101 ]


The foreskin has also been depicted in art from different historical ages:


The  G-spot , also called the  Gräfenberg spot  (for German gynecologist  Ernst Gräfenberg ), is characterized as an  erogenous  area of the  vagina  that, when stimulated, may lead to strong  sexual arousal , powerful  orgasms  and potential  female ejaculation . [ 1 ]  It is typically reported to be located 5–8 cm (2–3 in) up the front (anterior) vaginal wall between the vaginal opening and the  urethra  and is a sensitive area that may be part of the  female prostate . [ 2 ] [ 3 ]


The existence of the G-spot has not been proven, nor has the source of female ejaculation. [ 4 ] [ 5 ]  Although the G-spot has been studied since the 1940s, [ 2 ]  disagreement persists over its existence as a distinct structure, definition and location. [ 4 ] [ 6 ] [ 7 ]  The G-spot may be an extension of the  clitoris , which together may be the cause of orgasms experienced vaginally. [ 7 ] [ 8 ] [ 9 ]   Sexologists  and other researchers are concerned that women may consider themselves to be dysfunctional if they do not experience G-spot stimulation, and emphasize that not experiencing it is normal. [ 5 ]


Two primary methods have been used to define and locate the G-spot as a sensitive area in the  vagina : self-reported levels of arousal during stimulation, and stimulation of the G-spot leading to female ejaculation. [ 6 ]   Ultrasound  technology has also been used to identify  physiological  differences between women, and changes to the G-spot region during sexual activity. [ 10 ] [ 11 ]


The location of the G-spot is typically reported as being about 50 to 80 mm (2 to 3 in) inside the vagina, on the front wall. [ 2 ] [ 12 ]  For some women, stimulating this area creates a more intense orgasm than clitoral stimulation. [ 11 ]  The G-spot area has been described as needing direct  stimulation , such as two fingers pressed deeply into it. [ 13 ]  Attempting to stimulate the area through  sexual penetration , especially in the  missionary position , is difficult because of the particular angle of penetration required. [ 2 ]


Women usually need direct  clitoral  stimulation in order to orgasm, [ 15 ] [ 16 ]  and G-spot stimulation may be best achieved by using both  manual stimulation  and vaginal penetration. [ 2 ]  A  yoni massage  also includes manual stimulation of the G-spot. [ 17 ]


Sex toys  are available for G-spot stimulation. One common sex toy is the specially-designed  G-spot vibrator , which is a  phallic   vibrator  that has a curved tip and attempts to make G-spot stimulation easy. [ 18 ]  G-spot vibrators are made from the same materials as regular vibrators, ranging from hard plastic, rubber,  silicone ,  jelly , or any combination of them. [ 18 ]  The level of vaginal penetration when using a G-spot vibrator depends on the woman, because women's physiology is not always the same. The effects of G-spot stimulation when using the penis or a G-spot vibrator may be enhanced by additionally stimulating other  erogenous zones  on a woman's body, such as the clitoris or  vulva  as a whole. When using a G-spot vibrator, this may be done by manually stimulating the clitoris, including by using the vibrator as a  clitoral vibrator , or, if the vibrator is designed for it, by applying it so that it stimulates the head of the clitoris, the rest of the vulva and the vagina simultaneously. [ 18 ]


A 1981 case study reported that stimulation of the  anterior  vaginal wall made the area grow by fifty percent and that self-reported levels of arousal/orgasm were deeper when the G-spot was stimulated. [ 19 ] [ 20 ]  Another study, in 1983, examined eleven women by  palpating  the entire vagina in a clockwise fashion, and reported a specific response to stimulation of the anterior vaginal wall in four of the women, concluding that the area is the G-spot. [ 21 ] [ 22 ]  In a 1990 study, an anonymous questionnaire was distributed to 2,350 professional women in the United States and Canada with a subsequent 55% return rate. Of these respondents, 40% reported having a fluid release (ejaculation) at the moment of orgasm, and 82% of the women who reported the sensitive area (Gräfenberg spot) also reported ejaculation with their orgasms. Several variables were associated with this perceived existence of female ejaculation. [ 23 ]


Some research suggests that G-spot and clitoral orgasms are of the same origin.  Masters and Johnson  were the first to determine that the clitoral structures surround and extend along and within the labia. Upon studying women's  sexual response cycle  to different stimulation, they observed that both clitoral and vaginal orgasms had the same stages of physical response, and found that the majority of their subjects could only achieve clitoral orgasms, while a minority achieved vaginal orgasms. On this basis, Masters and Johnson argued that clitoral stimulation is the source of both kinds of orgasms, [ 24 ] [ 25 ]  reasoning that the clitoris is stimulated during penetration by friction against its hood. [ 26 ]


Researchers at the  University of L'Aquila , using ultrasonography, presented evidence that women who experience vaginal orgasms are statistically more likely to have thicker tissue in the anterior vaginal wall. [ 11 ]  The researchers believe these findings make it possible for women to have a rapid test to confirm whether or not they have a G-spot. [ 27 ]  Professor of  genetic epidemiology , Tim Spector, who co-authored research questioning the existence of the G-spot and finalized it in 2009, also hypothesizes thicker tissue in the G-spot area; he states that this tissue may be part of the clitoris and is not a separate erogenous zone. [ 28 ]


Supporting Spector's conclusion is a study published in 2005 which investigates the size of the clitoris – it suggests that clitoral tissue extends into the anterior wall of the vagina. The main researcher of the studies, Australian  urologist   Helen O'Connell , asserts that this interconnected relationship is the physiological explanation for the conjectured G-spot and experience of vaginal orgasms, taking into account the stimulation of the internal parts of the clitoris during vaginal penetration. While using  MRI  technology, O'Connell noted a direct relationship between the legs or roots of the clitoris and the erectile tissue of the "clitoral bulbs" and corpora, and the distal urethra and vagina. "The vaginal wall is, in fact, the clitoris," said O'Connell. "If you lift the skin off the vagina on the side walls, you get the bulbs of the clitoris – triangular, crescental masses of erectile tissue." [ 8 ]  O'Connell et al., who performed dissections on the female genitals of  cadavers  and used photography to map the structure of nerves in the clitoris, were already aware that the clitoris is more than just its glans and asserted in 1998 that there is more erectile tissue associated with the clitoris than is generally described in anatomical textbooks. [ 12 ] [ 25 ]  They concluded that some females have more extensive clitoral tissues and nerves than others, especially having observed this in young cadavers as compared to elderly ones, [ 12 ] [ 25 ]  and therefore whereas the majority of females can only achieve orgasm by direct stimulation of the external parts of the clitoris, the stimulation of the more generalized tissues of the clitoris via intercourse may be sufficient for others. [ 8 ]


French researchers Odile Buisson and  Pierre Foldès  reported similar findings to those of O'Connell's. In 2008, they published the first complete 3D  sonography  of the stimulated clitoris, and republished it in 2009 with new research, demonstrating the ways in which erectile tissue of the clitoris engorges and surrounds the vagina. On the basis of this research, they argued that women may be able to achieve vaginal orgasm via stimulation of the G-spot because the highly innervated clitoris is pulled closely to the anterior wall of the vagina when the woman is sexually aroused and during vaginal penetration. They assert that since the front wall of the vagina is inextricably linked with the internal parts of the clitoris, stimulating the vagina without activating the clitoris may be next to impossible. [ 10 ] [ 29 ] [ 30 ] [ 31 ]  In their 2009 published study, the "coronal planes during perineal contraction and finger penetration demonstrated a close relationship between the root of the clitoris and the anterior vaginal wall". Buisson and Foldès suggested "that the special sensitivity of the lower anterior vaginal wall could be explained by pressure and movement of clitoris's root during a vaginal penetration and subsequent perineal contraction". [ 10 ] [ 30 ]


In 2001, the  Federative Committee on Anatomical Terminology  accepted  female prostate  as a second term for the Skene's gland, which is believed to be found in the G-spot area along the walls of the urethra. The male prostate is biologically  homologous  to the Skene's gland; [ 32 ]  it has been unofficially called the male G-spot because it can also  be used as an erogenous zone . [ 1 ] [ 33 ]


Regnier de Graaf , in 1672, observed that the secretions (female ejaculation) by the erogenous zone in the vagina lubricate "in agreeable fashion during coitus". Modern scientific hypotheses linking G-spot sensitivity with female ejaculation led to the idea that non-urine female ejaculate may originate from the Skene's gland, with the Skene's gland and male prostate acting similarly in terms of prostate-specific antigen and prostate-specific  acid phosphatase  studies, [ 5 ] [ 34 ]  which led to a trend of calling the Skene's glands the female prostate. [ 34 ]  Additionally, the enzyme  PDE5  (involved with  erectile dysfunction ) has additionally been associated with the G-spot area. [ 35 ]  Because of these factors, it has been argued that the G-spot is a system of  glands  and  ducts  located within the anterior (front) wall of the vagina. [ 13 ]  A similar approach has linked the G-spot with the  urethral sponge . [ 36 ] [ 37 ]


G-spot amplification (also called G-spot augmentation or the G-Shot) is a procedure intended to temporarily increase pleasure in sexually active women with normal sexual function, focusing on increasing the size and sensitivity of the G-spot. G-spot amplification is performed by attempting to locate the G-spot and noting measurements for future reference. After numbing the area with a local anesthetic, human engineered  collagen  is then injected directly under the  mucosa  in the area the G-spot is concluded to be in. [ 13 ] [ 38 ]


A position paper published by the  American College of Obstetricians and Gynecologists  in 2007 warns that there is no valid medical reason to perform the procedure, which is not considered routine or accepted by the College; and it has not been proven to be safe or effective. The potential risks include sexual dysfunction, infection, altered sensation,  dyspareunia , adhesions and scarring. [ 13 ]  The College position is that it is untenable to recommend the procedure. [ 39 ]  The procedure is also not approved by the  Food and Drug Administration  or the  American Medical Association , and no  peer-reviewed  studies have been accepted to account for either safety or effectiveness of this treatment. [ 40 ]


In addition to general skepticism among gynecologists, sexologists and other researchers that the G-spot exists, [ 4 ] [ 5 ] [ 6 ] [ 7 ]  a team at  King's College London  in late 2009 suggested that its existence is subjective. They acquired the largest sample size of women to date – 1,800 – who are pairs of twins, and found that the twins did not report a similar G-spot in their questionnaires. The research, headed by Tim Spector, documents a 15-year study of the twins, identical and non-identical. According to the researchers, if one identical twin reported having a G-spot, it was more likely that the other would too, but this pattern did not materialize. [ 5 ] [ 10 ]  Study co-author Andrea Burri believes: "It is rather irresponsible to claim the existence of an entity that has never been proven and pressurise women and men too." [ 41 ]  She stated that one of the reasons for the research was to remove feelings of "inadequacy or underachievement" for women who feared they lacked a G-spot. [ 42 ]  Researcher  Beverly Whipple  dismissed the findings, commenting that twins have different sexual partners and techniques, and that the study did not properly account for lesbian or bisexual women. [ 43 ]


Petra Boynton, a British scientist who has written extensively on the G-spot debate, is also concerned about the promotion of the G-spot leading women to feel "dysfunctional" if they do not experience it. "We're all different. Some women will have a certain area within the vagina which will be very sensitive, and some won't — but they won't necessarily be in the area called the G spot," she stated. "If a woman spends all her time worrying about whether she is normal, or has a G spot or not, she will focus on just one area, and ignore everything else. It's telling people that there is a single, best way to have sex, which isn't the right thing to do." [ 44 ]


G-spot proponents are criticized for giving too much credence to  anecdotal evidence , and for questionable investigative methods; for instance, the studies which have yielded positive evidence for a precisely located G-spot involve small participant samples. [ 4 ] [ 6 ]  While the existence of a greater concentration of nerve endings at the lower third (near the entrance) of the vagina is commonly cited, [ 1 ] [ 5 ] [ 9 ] [ 45 ]  some scientific examinations of vaginal wall innervation have shown no single area with a greater density of nerve endings. [ 5 ] [ 6 ]


Several researchers also consider the connection between the Skene's gland and the G-spot to be weak. [ 6 ] [ 46 ]  The urethral sponge, however, which is also hypothesized as the G-spot, contains sensitive nerve endings and erectile tissue. [ 36 ] [ 37 ]  Sensitivity is not determined by neuron density alone: other factors include the branching patterns of neuron terminals and cross or collateral innervation of neurons. [ 47 ]  While G-spot opponents argue that because there are very few tactile nerve endings in the vagina and that therefore the G-spot cannot exist, G-spot proponents argue that vaginal orgasms rely on pressure-sensitive nerves. [ 4 ]


The G-spot having an anatomical relationship with the clitoris has been challenged by Vincenzo Puppo, who, while agreeing that the clitoris is the center of female sexual pleasure, disagrees with Helen O'Connell and other researchers' terminological and anatomical descriptions of the clitoris. He stated, "Clitoral bulbs is an incorrect term from an embryological and anatomical viewpoint, in fact the bulbs do not develop from the phallus, and they do not belong to the clitoris". He says that  clitoral bulbs  "is not a term used in human anatomy" and that  vestibular bulbs  is the correct term, adding that gynecologists and sexual experts should inform the public with facts instead of hypotheses or personal opinions. "[C]litoral/vaginal/uterine orgasm, G/A/C/U spot orgasm, and female ejaculation, are terms that should not be used by sexologists, women, and mass media", he said, further commenting that the "anterior vaginal wall is separated from the posterior urethral wall by the urethrovaginal septum (its thickness is 10–12 mm)" and that the "inner clitoris" does not exist. "The female perineal urethra, which is located in front of the anterior vaginal wall, is about one centimeter in length and the G-spot is located in the pelvic wall of the urethra, 2–3 cm into the vagina", Puppo stated. He believes that the penis cannot come in contact with the congregation of multiple nerves/veins situated until the angle of the clitoris, detailed by  Georg Ludwig Kobelt , or with the roots of the clitoris, which do not have sensory receptors or erogenous sensitivity, during vaginal intercourse. He did, however, dismiss the orgasmic definition of the G-spot that emerged after Ernst Gräfenberg, stating that "there is no anatomical evidence of the vaginal orgasm which was invented by Freud in 1905, without any scientific basis". [ 48 ]


Puppo's belief that there is no anatomical relationship between the vagina and clitoris is contrasted by the general belief among researchers that vaginal orgasms are the result of clitoral stimulation; they maintain that clitoral tissue extends, or is at least likely stimulated by the clitoral bulbs, even in the area most commonly reported to be the G-spot. [ 7 ] [ 9 ] [ 31 ] [ 49 ]  "My view is that the G-spot is really just the extension of the clitoris on the inside of the vagina, analogous to the base of the male penis", said researcher Amichai Kilchevsky. Because female fetal development is the "default" direction of fetal development in the absence of substantial exposure to male hormones and therefore the penis is essentially a clitoris enlarged by such hormones, Kilchevsky believes that there is no evolutionary reason why females would have two separate structures capable of producing orgasms and blames the porn industry and "G-spot promoters" for "encouraging the myth" of a distinct G-spot. [ 49 ]


The general difficulty of achieving vaginal orgasms, which is a predicament that is likely due to nature easing the process of childbearing by drastically reducing the number of vaginal nerve endings, [ 1 ] [ 4 ] [ 45 ]   challenge arguments that vaginal orgasms help encourage sexual intercourse in order to facilitate reproduction. [ 7 ] [ 26 ]  O'Connell stated that focusing on the G-spot to the exclusion of the rest of a woman's body is "a bit like stimulating a guy's testicles without touching the penis and expecting an orgasm to occur just because love is present". She stated that it "is best to think of the clitoris, urethra, and vagina as one unit because they are intimately related". [ 50 ]   Ian Kerner  stated that the G-spot may be "nothing more than the roots of the clitoris crisscrossing the urethral sponge". [ 50 ]


A  Rutgers University  study, published in 2011, was the first to map the female genitals onto the sensory portion of the brain, and supports the possibility of a distinct G-spot. When the research team asked several women to stimulate themselves in a  functional magnetic resonance  (fMRI) machine, brain scans showed stimulating the clitoris, vagina and cervix lit up distinct areas of the women's sensory cortex, which means the brain registered distinct feelings between stimulating the clitoris, the cervix and the vaginal wall – where the G-spot is reported to be. [ 29 ] [ 51 ] [ 52 ]  "I think that the bulk of the evidence shows that the G-spot is not a particular thing," stated  Barry Komisaruk , head of the research findings. "It's not like saying, 'What is the thyroid gland?' The G-spot is more of a thing like New York City is a thing. It's a region, it's a convergence of many different structures". [ 7 ]


In 2009,  The Journal of Sexual Medicine  held a debate for both sides of the G-spot issue, concluding that further evidence is needed to validate the existence of the G-spot. [ 5 ]  In 2012, scholars Kilchevsky, Vardi, Lowenstein and Gruenwald stated in the journal, "Reports in the public media would lead one to believe the G-spot is a well-characterized entity capable of providing extreme sexual stimulation, yet this is far from the truth". The authors cited that dozens of trials have attempted to confirm the existence of a G-spot using surveys, pathologic specimens, various imaging modalities, and biochemical markers, and concluded:


The surveys found that a majority of women believe a G-spot actually exists, although not all of the women who believed in it were able to locate it. Attempts to characterize vaginal innervation have shown some differences in nerve distribution across the vagina, although the findings have not proven to be universally reproducible. Furthermore, radiographic studies have been unable to demonstrate a unique entity, other than the clitoris, whose direct stimulation leads to vaginal orgasm. Objective measures have failed to provide strong and consistent evidence for the existence of an anatomical site that could be related to the famed G-spot. However, reliable reports and anecdotal testimonials of the existence of a highly sensitive area in the distal anterior vaginal wall raise the question of whether enough investigative modalities have been implemented in the search of the G-spot. [ 7 ]


A 2014 review from  Nature Reviews Urology  reported that "no single structure consistent with a distinct G-spot has been identified". [ 53 ]


The release of fluids had been seen by medical practitioners as beneficial to health. Within this context, various methods were used over the centuries to release "female seed" (via  vaginal lubrication  or female ejaculation) as a treatment for  suffocation ex semine retento  (suffocation of the womb),  female hysteria  or  green sickness . Methods included a  midwife  rubbing the walls of the vagina or insertion of the penis or penis-shaped objects into the vagina. [ 54 ]  In the book  History of V ,  Catherine Blackledge  [ pl ]  lists old terms for what she believes refer to the female prostate (the Skene's gland), including  the little stream ,  the black pearl  and  palace of yin  in China,  the skin of the earthworm  in Japan, and  saspanda nadi  in the India sex manual  Ananga Ranga . [ 55 ]


The 17th-century Dutch physician Regnier de Graaf described female ejaculation and referred to an erogenous zone in the vagina that he linked as homologous with the male prostate; this zone was later reported by the German gynecologist  Ernst Gräfenberg . [ 56 ]  Coinage of the term  G-spot  has been credited to Addiego et al. in 1981, named after Gräfenberg, [ 57 ]  and to Alice Kahn Ladas and  Beverly Whipple  et al. in 1982. [ 21 ]  Gräfenberg's 1940s research, however, was dedicated to urethral stimulation; Gräfenberg stated, "An erotic zone always could be demonstrated on the anterior wall of the vagina along the course of the urethra". [ 58 ]  The concept of the G-spot entered popular culture with the 1982 publication of  The G Spot and Other Recent Discoveries About Human Sexuality  by Ladas, Whipple and Perry, [ 21 ]  but it was criticized immediately by  gynecologists : [ 2 ] [ 59 ]  some of them denied its existence as the absence of arousal made it less likely to observe, and autopsy studies did not report it. [ 2 ]


The  human sexual response cycle  is a four-stage model of  physiological responses  to  sexual stimulation , [ 1 ]  which, in order of their occurrence, are the  excitement , plateau,  orgasmic , and  resolution  phases. This physiological response model was first formulated by  William H. Masters and Virginia E. Johnson , in their 1966 book  Human Sexual Response . [ 1 ] [ 2 ]  Since that time, other models regarding human sexual response have been formulated by several scholars who have criticized certain inaccuracies in the human sexual response cycle model.


The  excitement phase  (also known as the  arousal phase  or  initial excitement phase ) is the first stage of the human sexual response cycle, which occurs as a result of physical or mental  erotic stimuli , such as  kissing ,  making out ,  fantasizing  or  viewing erotic images , that leads to  sexual arousal . During this stage, the body prepares for  sexual intercourse , initially leading to the plateau phase. [ 1 ]  There is wide socio-cultural variation regarding preferences for the length of foreplay and the stimulation methods used. [ 3 ]  Physical and emotional interaction and stimulation of the erogenous zones during foreplay usually establishes at least some initial arousal. [ citation needed ]


Among both sexes, the excitement phase results in an increase in heart rate, breathing rate, and a rise in  blood pressure . [ 1 ]  A survey in 2006 found that sexual arousal in about 82% of young females and 52% of young males arises or is enhanced by direct  stimulation of nipples , with only 7–8% reporting that it decreased their arousal. [ 4 ]   Vasocongestion  of the skin, commonly referred to as the  sex flush , will occur in approximately 50-75% of females and 25% of males. The sex flush tends to occur more often under warmer conditions and may not appear at all under cooler temperatures.


During the female sex flush, pinkish spots develop under the breasts, then spread to the breasts, torso, face, hands, soles of the feet, and possibly over the entire body. [ 1 ]  Vasocongestion is also responsible for the darkening of the clitoris and the walls of the vagina during sexual arousal. During the male sex flush, the coloration of the skin develops less consistently than in the female, but typically starts with the  epigastrium  (upper abdomen), spreads across the chest, then continues to the neck, face, forehead, back, and sometimes, shoulders and forearms. The sex flush typically disappears soon after orgasm occurs, but this may take up to two hours or so and, sometimes, intense sweating will occur simultaneously. The flush usually diminishes in reverse of the order in which it appeared. [ 2 ]


An increase in muscle tone ( myotonia ) of certain muscle groups, occurring voluntarily and involuntarily, begins during this phase among both sexes. [ 2 ] [ clarification needed ]  Also, the  external anal sphincter  may  contract  randomly upon contact (or later during  orgasm  without contact).


In males, the beginning of the excitement phase is observed when the  penis  becomes partially or fully  erect , often after only a few seconds of erotic stimulation. [ 1 ]  The erection may be partially lost and regained repeatedly during an extended excitement phase. Both  testicles  become drawn upward toward the  perineum , notably in  circumcised  males where less skin is available to accommodate the erection. Also, the  scrotum  can tense and thicken during the erection process.


In females, the excitement phase can last from several minutes to several hours. The onset of  vasocongestion  results in swelling of the woman's clitoris, labia minora and vagina. The muscle that surrounds the vaginal opening grows tighter and the uterus elevates and grows in size. The vaginal walls begin to produce a  lubricating organic liquid . [ 1 ]  Meanwhile, the breasts increase slightly in size and nipples become hardened and erect.


The  plateau phase  is the period of sexual excitement prior to  orgasm . The phase is characterised by an increased circulation and heart rate in both sexes, increased sexual pleasure with increased stimulation and further increased muscle tension. Also, respiration continues at an elevated level. [ 1 ]  Prolonged time in the plateau phase without progression to the orgasmic phase may result in  sexual frustration .


During this phase, the male  urethral sphincter  contracts (preventing  urine  from mixing with  semen , and  retrograde ejaculation ) and muscles at the base of the penis begin a steady rhythmic contraction. [ 1 ]  Males may start to secrete seminal fluid or  pre-ejaculatory  fluid and the  testicles  rise closer to the body. [ 2 ]


The plateau stage in females is basically a continuation of the same changes evident in the excitement stage. The  clitoris  becomes extremely sensitive and withdraws slightly, and the  Bartholin glands  produce further  lubrication . The tissues of the outer third of the vagina swell, and the  pubococcygeus muscle  tightens, reducing the diameter of the opening of the vagina. [ 1 ]  Masters and Johnson refer to the changes that take place during the plateau stage as the  orgasmic platform .


Orgasm is experienced by both males and females, ending the plateau phase of the sexual response cycle. Orgasm is accompanied by quick cycles of  muscle contraction  in the lower  pelvic muscles , which surround both the anus and the  primary sexual organs . [ clarification needed ]  Orgasms are often associated with other  involuntary  actions, including  vocalizations  and  muscular spasms  in other areas of the body and a generally  euphoric  sensation. Heart rate is increased even further. [ 1 ]   Tantric sex  practices may seek to diminish the goal of achieving orgasm, which is frequently a common goal of sexual intercourse.


In males, orgasm is usually associated with  ejaculation . Each ejaculation is accompanied with continuous pulses of sexual pleasure, especially in the penis and surrounding area. [ 1 ]  Other sensations may be felt strongly among the lower spine or lower back. The first and second convulsions are usually the most intense in sensation and produce the greatest quantity of semen. Thereafter, each contraction is associated with a diminishing volume of semen and a milder sensation of pleasure. [ 1 ]


Women also experience  uterine  and  vaginal   contractions . Orgasms in females can vary widely from individual to individual. They are commonly associated with an increase in  vaginal lubrication , a tightening of the vaginal walls and overall pleasure. [ 1 ]  For some women, there is also a possibility of  female ejaculation .


The  resolution phase  occurs after orgasm and allows the muscles to relax, blood pressure to drop and the body to slow down from its excited state. [ 1 ]  The refractory period, which is part of the resolution phase, is the time frame in which usually a man is unable to orgasm again, though women can also experience a refractory period.


Masters and Johnson described the two-stage detumescence of the penis: In the first stage, the penis decreases from its erect state to about 50 percent larger than its flaccid state. This occurs during the refractory period. In the second stage (and after the refractory period is finished), the penis decreases in size and returns to being flaccid. [ 2 ]  It is generally impossible for men to achieve orgasm during the refractory period. [ 2 ] [ 5 ] [ 6 ]  Masters and Johnson argue that this period must end before men can become aroused again. [ 7 ]


Although, due to the refractory period, it is rare for men to achieve  multiple orgasms , [ 8 ] [ 9 ]  some men have reported having multiple, consecutive orgasms, particularly without ejaculation. [ 10 ]  Multiple orgasms are more commonly reported in very young men than in older men. [ 10 ]  In younger men, the refractory period may only last a few minutes, but last more than an hour in older men. [ 11 ]


According to Masters and Johnson, women have the ability to orgasm again very quickly, as long as they have effective stimulation. As a result, they are able to have  multiple orgasms  in a relatively short period of time. [ 2 ] [ 7 ]  Though generally reported that women do not experience a refractory period and thus can experience an additional orgasm, or multiple orgasms, soon after the first, [ 5 ] [ 6 ]  some sources state that men and women experience a refractory period because women may also experience a period after orgasm in which further sexual stimulation does not produce excitement. [ 12 ] [ 13 ]  For some women, the clitoris is very sensitive after climax, making additional stimulation initially painful. [ 14 ]  After the initial orgasm, subsequent orgasms for women may also be stronger or more pleasurable as the stimulation accumulates. [ 14 ] [ 15 ]


Masters and Johnson argue that, despite some minor differences, sexual responses in both men and women are fundamentally similar. [ 1 ] [ 2 ]  However, researchers have argued that there are many differences between men and women in terms of their response. First, Masters and Johnson put forth one model for men, but three different models for women. They stated that men's sexual response only differs in terms of duration; showing different models would, thus, be repetitive. Women, on the other hand, they state can have responses that differ in both intensity and duration. [ 2 ]  These variations can pose problems because psychologists have argued that not everyone fits this model; for example, most women do not orgasm during penetrative sexual intercourse. [ 16 ]  Masters and Johnson also equate a man's erection with a woman's vaginal lubrication during the excitement phase; Roy Levin states that this observation is false. A woman's clitoris is the  anatomical parallel  to a man's penis. As a result,  clitoral swelling  would be the equivalent of a man's  erection . [ 17 ]


Another aspect is the lack of concordance between subjective  sexual arousal  and genital arousal. Research by  Meredith L. Chivers  and  J. Michael Bailey  indicates that men tend to show category-specific arousal; that is, they are sexually aroused by their preferred gender. However, women show category non-specificity: Their genitals show arousal to both preferred and non-preferred genders. [ 18 ] [ 19 ]  Even though women reported being subjectively aroused to, for example, a man and woman engaging in sexual activity, their genitals also show sexual arousal to two men engaging in sexual activity, two women doing so, and even non-human animals having sex. [ 20 ]


Overall, Masters and Johnson's model appears to be a better example of men's sexual response than women's. [ 21 ]


There has been much research conducted based on Masters and Johnson's model. However, inaccuracies have been found in the descriptions of the stages of sexual response. For example, Roy Levin identified a few areas of the model that had not been touched upon. [ 22 ]  First, Masters and Johnson state that only the vagina is lubricated during the arousal stage; Levin argues that the labia produce their own lubricant. Levin also presents research which shows that the first signs of physiological arousal in women is increased blood flow to the vagina, not lubrication. He also dispels information about men and their sexual response; Masters and Johnson report that pleasure was positively associated with the volume of ejaculate released, but Rosenberg, Hazzard, Tallman and Ohl gave a group of men a questionnaire and found that significantly more men reported that physical pleasure was associated with the strength of the ejaculation compared to the volume. [ 23 ]  Moreover, some researchers have found that some men can have multiple orgasms, despite what Masters and Johnson had reported. [ 24 ] [ 25 ]


Some researchers have also criticized how Masters and Johnson define sexual response solely in terms of physiology; for example, Everaerd, and Laan have found that sexual arousal can be defined as an emotional state in both men and women. [ 26 ]  Other researchers have stated that there is a lack of concordance between women's subjective sexual arousal and their genital arousal. [ 16 ] [ 18 ]  Rosemary Basson argues that this model poorly explains women's sexual response, especially for those who are in long-term relationships. [ 16 ] [ 27 ]


Shortly after Masters and Johnson published their book, several scholars criticized their model of the human sexual response cycle. For example,  Helen Singer Kaplan  argued that Masters and Johnson only evaluated sexual response from a physiological perspective, and that psychological, emotional, and cognitive factors need to be taken into consideration. As a result, she proposed her model of the sexual response cycle which includes three phases: desire, excitement, and orgasm. She argues that these three phases are interconnected, yet they have different  neurophysiological  mechanisms. [ 28 ]  Similarly, Paul Robinson argued that the excitement and plateau phases are the same; he criticizes Masters and Johnson's work for not clearly distinguishing when the excitement phase ends, and when the plateau phase begins. [ 29 ]


Another model that has been put forth is the  incentive-motivation model . The model explains that the desire for sex comes from an interaction between a sensitive sexual response system and stimuli that are present in the environment. Researchers argue that this model supports the idea that  sexual desire  is not spontaneous. Furthermore, this model implies that the case is not that one has sex because one feels sexual desire; rather, the case is that one feels sexual desire because one has sex. [ 30 ]


Rosemary Basson proposed an alternative model of sexual response. She argues that the linear model is good at explaining men's sexual response but it poorly explains women's sexual responses; thus, she puts forth a  circular model . [ 27 ]  She states that closeness or attachment to a partner increases the effectiveness of sexual stimulation. This leads to enhanced sexual arousal, which may ultimately result in orgasm. Consequently, this positive sexual arousal continues the sexual desire that women feel, and this desire increases intimacy with the partner. [ 27 ]  Other researchers have attempted to evaluate women's sexual functioning in terms of this new model but have found contradictory results. In one study conducted by Giles and McCabe, they found that the linear model of sexual response was a good predictor of women's sexual functioning (and dysfunction), while the circular model was a poor predictor. [ 31 ]  Once they modified the pathways of the model, the circular model then became a good predictor of sexual functioning. [ 31 ]  In another study looking at Malaysian women, researchers found that the circular model was actually a good predictor of women's sexual desire and arousal. [ 32 ]  More research needs to be done in this area to show whether the circular model more accurately describes women's sexual response.


The human sexual response cycle set the foundation for studying and categorizing sexual dysfunctions in men and women. [ 33 ] [ 34 ]  There are four main categories of sexual dysfunctions:  desire disorders ,  arousal disorders ,  orgasm disorders , and  sexual pain disorders . They are still categorized as such in the  DSM-IV-TR . Recent research, however, suggests that the current model of sexual response needs to be revised to better treat these dysfunctions. One reason is that there is considerable overlap between sexual dysfunctions in women. [ 35 ]  One study found that in patients with  hypoactive sexual desire disorder  (HSDD), 41% of women had at least one other sexual dysfunction and 18% had diagnoses in all three categories (that is, in desire, arousal, and orgasm disorders). [ 36 ]


Another issue is that, among women, there is a discrepancy between desire and arousal. After Cynthia Graham critically evaluated  female sexual arousal disorder  (FSAD), she found that women reported that, contrary to Masters and Johnson's model, sexual arousal sometimes preceded sexual desire; at other times, desire presented before arousal. [ 37 ]  Because of the high comorbidity rates between HSDD and FSAD, she would like to merge them to make the category "Sexual Interest/Arousal Disorder." Hartmann and colleagues summarize their views of the current model of the sexual response cycle and conclude that "by simply expanding and continuing DSM-IV criteria and the traditional response cycle classification systems, it is impossible to come to diagnostic categories and subtypes that adequately reflect real-life female sexual problems". [ 38 ]


Hypersexuality  is a medical condition that causes unwanted or excessive  sexual arousal , causing people to engage in or think about  sexual activity  to a point of  distress  or  impairment . [ 1 ]  It is controversial whether it should be included as a  clinical diagnosis [ 1 ] [ 2 ]  used by  mental healthcare  professionals.  Nymphomaniac  and  sex maniac  were terms previously used for the condition in women and men, respectively.


Hypersexuality may be a primary condition, or the symptom of other medical conditions or disorders such as  Klüver–Bucy syndrome ,  bipolar disorder ,  brain injury  and  dementia . Hypersexuality may also present as a side effect of medication, such as  dopaminergic  drugs used to treat  Parkinson's disease . [ 3 ] [ 4 ]  Frontal lesions caused by brain injury, strokes, and frontal lobotomy are thought to cause hypersexuality in individuals who have had these conditions. [ 5 ]  Clinicians have yet to reach a consensus over how best to describe hypersexuality as a primary condition, [ 6 ] [ 7 ] [ 8 ]  or to determine the appropriateness of describing such behaviors and impulses as a separate pathology.


Hypersexual behaviors are viewed variously by clinicians and therapists as a type of  obsessive-compulsive disorder  (OCD) or "OCD-spectrum disorder", an addiction, [ 9 ] [ 10 ] [ 11 ]  or a disorder of impulsivity. A number of authors do not acknowledge such a pathology, [ 12 ]  and instead assert that the condition merely reflects a cultural dislike of exceptional sexual behavior. [ 13 ] [ 14 ]


Consistent with there not being any consensus over what causes hypersexuality, [ 15 ]  authors have used many different labels to refer to it, sometimes interchangeably, but often depending on which theory they favor or which specific behavior they have studied or have done research on; related or obsolete terms include  compulsive masturbation ,  compulsive sexual behavior , [ 16 ] [ 17 ]   cybersex addiction ,  erotomania , "excessive sexual drive", [ 18 ]   hyperphilia , [ 19 ]  hypersexuality, [ 20 ] [ 21 ]  hypersexual disorder, [ 22 ]  problematic hypersexuality, [ 23 ]   sexual addiction , sexual compulsivity, [ 24 ]  sexual dependency, [ 14 ]  sexual impulsivity, [ 25 ]  "out of control sexual behavior", [ 26 ]  and  paraphilia -related disorder. [ 27 ] [ 28 ] [ 29 ]


Due to the controversy surrounding the diagnosis of hypersexuality, there is no one generally accepted definition and measurement for hypersexuality, making it difficult to truly determine the prevalence. Thus, the prevalence can vary depending on how it is defined and measured. Overall, hypersexuality is estimated to affect 2–6% of the population, and may be higher in certain populations like men, those who have been traumatized, and sex offenders. [ 30 ] [ 31 ] [ 32 ]


There is little consensus among experts as to the causes of hypersexuality. Some research suggests that some cases can be linked to biochemical or physiological changes that accompany  dementia , as dementia can lead to disinhibition. [ 33 ]  Psychological needs also complicate the biological explanation, which identifies the temporal/frontal lobe of the brain as the area for regulating libido. Injuries to this part of the brain increase the risk of aggressive behavior and other behavioral problems including personality changes and "socially inappropriate" sexual behavior such as hypersexuality. [ 34 ]  The same symptom can occur after unilateral temporal  lobotomy . [ 35 ]  There are other biological factors that are associated with hypersexuality such as premenstrual changes, and the exposure to  virilising  hormones in childhood or in utero. [ 36 ]


In research involving the use of  antiandrogens  to reduce undesirable sexual behaviour such as hypersexuality, testosterone has been found to be necessary, but not sufficient, for sexual drive. [ 36 ]  A lack of physical closeness and forgetfulness of the recent past were proposed as other potential factors (specifically in the context of hypersexual behavior exhibited by people suffering from  dementia ). [ 37 ]


Pathogenic overactivity of the  dopaminergic   mesolimbic pathway  in the brain—forming either psychiatrically, during  mania , [ 38 ]  or pharmacologically, as a side effect of  dopamine agonists , specifically  D 3 -preferring agonists [ 39 ] [ 40 ] —is associated with various  addictions [ 41 ] [ 42 ]  and has been shown to result among some in overindulgent, sometimes hypersexual, behavior. [ 38 ] [ 39 ] [ 40 ]   HPA axis  dysregulation has been associated with hypersexual disorder. [ 43 ]


The American Association for Sex Addiction Therapy acknowledges biological factors as contributing causes of sex addiction. Other associated factors include psychological components (which affect mood and motivation as well as psychomotor and cognitive functions [ 44 ] ), spiritual control, mood disorders, sexual trauma, and  intimacy anorexia  as causes or type of sex addiction. [ 45 ] [ better source needed ]


Hypersexuality is known to present itself as a symptom in connection to a number of mental and neurological disorders. Some people with  borderline personality disorder  (sometimes referred to as BPD) can be markedly impulsive, seductive, and extremely sexual.  Sexual promiscuity ,  sexual obsessions , and hypersexuality are very common symptoms for both men and women with BPD. On occasion for some there can be extreme forms of  paraphilic drives and desires . "Borderline" patients, due in the opinion of some to the use of  splitting , experience love and  sexuality  in unstable ways. [ 46 ]


People with  bipolar disorder  may often display tremendous swings in sex drive depending on their mood. [ 47 ] [ 48 ]  As defined in the DSM-IV-TR, hypersexuality can be a symptom of  hypomania  or  mania  in  bipolar disorder  or  schizoaffective disorder .  Pick's disease  causes damage to the temporal/frontal lobe of the brain; people with Pick's disease show a range of socially inappropriate behaviors. [ 49 ]


Several neurological conditions such as  Alzheimer's disease ,  autism , [ 50 ] [ 51 ]  various types of brain injury, [ 52 ]   Klüver–Bucy syndrome , [ 53 ]   Kleine–Levin syndrome , [ 54 ]   Epilepsy [ 55 ]  and many neurodegenerative diseases can cause hypersexual behavior. Sexually inappropriate behavior has been shown to occur in 7–8% of Alzheimer's patients living at home, at a care facility or in a hospital setting. Hypersexuality has also been reported to result as a side-effect of some medications used to treat  Parkinson's disease . [ 56 ] [ 57 ]  Some  recreationally used drugs , such as  methamphetamine , may also contribute to hypersexual behavior. [ 58 ]


A positive link between the severity of dementia and occurrence of inappropriate behavior has also been found. [ 59 ]  Hypersexuality can be caused by dementia in a number of ways, including  disinhibition  due to organic disease, misreading of social cues,  understimulation , the persistence of learned sexual behavior after other behaviours have been lost, and the side-effects of the drugs used to treat dementia. [ 60 ]  Other possible causes of dementia-related hypersexuality include an inappropriately expressed psychological need for  intimacy  and forgetfulness of the recent past. [ 37 ]  As this illness progresses, increasing hypersexuality has been theorized to sometimes compensate for declining self-esteem and cognitive function. [ 37 ]


Symptoms of hypersexuality are also similar to those of sexual addiction in that they embody similar traits. These symptoms include the inability to be intimate (intimacy anorexia), depression and bipolar disorders. [ 61 ]  The resulting hypersexuality may have an impact in the person's social and occupational domains if the underlying symptoms have a large enough systemic influence. [ 62 ] [ 63 ]


In 2010, a proposal to add  Sexual Addiction  to the  Diagnostic and Statistical Manual of Mental Disorders  (DSM) system has failed to get support of the  American Psychiatric Association  (APA). [ 64 ] [ 65 ] [ 66 ]  The DSM does include an entry called Sexual Disorder Not Otherwise Specified (Sexual Disorder NOS) to apply to, among other conditions, "distress about a pattern of repeated sexual relationships involving a succession of lovers who are experienced by the individual only as things to be used". [ 67 ]  As of December 2024 [update]  the DSM-5-TR, does not recognize a diagnosis of sexual addiction. [ 68 ]


The  International Statistical Classification of Diseases and Related Health Problems  (ICD-10) of the  World Health Organization  (WHO), includes two relevant entries. One is "Excessive Sexual Drive" (coded F52.7), [ 69 ]  which is divided into satyriasis for males and nymphomania for females. The other is "Excessive Masturbation" or "Onanism (excessive)" (coded F98.8). [ 70 ]


In 1988, Levine and Troiden questioned whether it makes sense to discuss hypersexuality at all, arguing that labeling sexual urges "extreme" merely stigmatizes people who do not conform to the  norms  of their culture or peer group, and that sexual compulsivity be a myth. [ 13 ]  However, and in contrast to this view, 30 years later in 2018, the  ICD-11  created a new condition classification,  compulsive sexual behavior , to cover "a persistent pattern of failure to control intense, repetitive sexual impulses or urges resulting in repetitive sexual behaviour". It classifies this "failure to control" as an abnormal mental health condition. [ 71 ] [ 72 ]


Individuals with hypersexuality are at a higher risk for various negative consequences, such as contracting STIs, committing sexual abuse, damaging relationships, and developing other addictions. 27.5% of affected individuals contracted an STI on at least one occasion as a result of their hypersexual behavior, and 12% of affected individuals engage in excessive, unprotected sex with multiple anonymous partners. [ 73 ] [ 74 ]  Additionally, an overwhelming 89% affected individuals admit to engaging in sexual activities outside of their primary relationship. [ 73 ]  This can negatively affect one's interpersonal and sexual relationships. In fact, 22.8% of sex addicts have had a relationship end due to their behaviors.  [ 73 ]


Furthermore, those with hypersexuality are more likely to have had or acquire another addiction. Multiple addictions are also prevalent amongst affected individuals. Common co-occurring disorders and addictions hypersexual individuals include eating disorders, compulsive spending, chemical dependency, and uncontrollable gambling. [ 73 ]


Those seeking treatment for hypersexual behavior are a heterogeneous group, thus a thorough assessment is required to evaluate what kinds of behaviors and conditions need to be addressed and treated. It is essential for clinicians to conduct a comprehensive clinical interview with the patient, in which they address the history of their presenting problems, psychological history, sexual history, psychiatric history, mental health history, substance use history, and medical history. [ 75 ]  Understanding these facets of an individual exhibiting hypersexual behavior is crucial due to the diverse array of comorbid conditions potentially linked to hypersexuality. The presence of ongoing treatment for any coexisting conditions in the individual can also have an impact on their symptoms and subsequent therapeutic interventions. Supplemental information from a spouse or family member could also be used during assessments. [ 76 ]


In addition to this, various questionnaires and instruments may be used to further assess various aspects of an individual's behaviors and symptoms. Some common questionnaires that are used in assessments are the Sexual Inhibition/Sexual Excitation Scale, [ 77 ]  Intensity of Sexual Desire and Symptoms Scale, [ 78 ]  Compulsive Sexual Behavior Inventory, [ 79 ] [ 80 ]  Sexual Compulsivity Scale, [ 81 ]  and the Sexual Addiction Screening Test [ 82 ]  amongst others. Different instruments can also be used in assessments, including but not limited to the Clinical Global Impression Scale, [ 83 ]  Timeline Followback, [ 84 ]  Minnesota Multiphase Personality Inventory II, [ 85 ]  and the Millon Inventory. [ 86 ]


The first step to treat hypersexual behavior is to help the individual stop or control their urges. There are a multitude of different treatment options for those experiencing hypersexual behaviors, and many clinicians recommend a multifaceted approach. Treatment plans are created after assessing the individual, so treatment methods can vary depending on an individual's history, current symptoms, and any comorbid conditions they may have. Common treatment methods include cognitive-behavioral therapy, relapse-prevention therapy, psychodynamic psychosocial therapy, and psychopharmacological treatment, which can be implemented through individual therapy, couple's therapy, and/or group therapy.  [ 87 ]


The concept of hypersexuality as an addiction was started in the 1970s by former members of  Alcoholics Anonymous  who felt they experienced a similar lack of control and compulsivity with sexual behaviors as with alcohol. [ 13 ] [ 88 ]  Multiple  12-step style self-help groups  now exist for people who identify as sex addicts, including  Sex Addicts Anonymous ,  Sexaholics Anonymous ,  Sex and Love Addicts Anonymous , and  Sexual Compulsives Anonymous . Some hypersexual men may treat their condition with the usage of medication (such as  Cyproterone acetate ) or consuming foods considered to be  anaphrodisiacs . [ 89 ]  Other hypersexuals may choose a route of consultation, such as psychotherapy, self-help groups or counselling. [ 90 ]


Sexologists  have been using the term  hypersexuality  since the late 1800s, when  Krafft-Ebing  described several cases of extreme sexual behaviours in his seminal 1886 book,  Psychopathia Sexualis . [ 91 ] [ 15 ]  The author used the term "hypersexuality" to describe conditions that would now be termed  premature ejaculation . Terms to describe males with the condition include  donjuanist , [ 92 ]   satyromaniac , [ 93 ]   satyriac [ 94 ]  and  satyriasist , [ 95 ]  for women  clitoromaniac , [ 96 ]   nympho  and  nymphomaniac , [ 97 ]  for teleiophilic (attracted to adults)  heterosexual  women  andromaniac , [ 98 ]  while  hypersexualist ,  sexaholic , [ 99 ]   onanist ,  hyperphiliac  and  erotomaniac [ 100 ]  are gender neutral terms. [ 101 ]


Other, mostly historical, names are the  Messalina  complex, [ 102 ]  sexaholism, [ 103 ]  hyperlibido [ 104 ]  and furor uterinus. [ 105 ]   John Wilmot, 2nd Earl of Rochester  described hypersexuality in some of his literature. [ 106 ]


The  lovemap  is a concept originated by sexologist  John Money  in his discussions of how people develop their sexual preferences. Money defined it as "a developmental representation or template in the mind and in the brain depicting the idealized lover and the idealized program of sexual and erotic activity projected in imagery or actually engaged in with that lover." [ 1 ]


John Money first wrote the word  lovemap  in 1980 for an article later published under the title "Pairbonding and  Limerence ". Prior to that, Money discussed lovemaps in a precursory form with his students in lectures, employing the term as a replacement for the expression, "an idealized and highly idiosyncratic image." [ 2 ]  In a 1997 article in the controversial and non- peer reviewed  journal  Medical Hypotheses , Money revisited  the concept of 'love map' and expanded it to three categories,  haptoerotic  (cutaneous),  morphoerotic  (visual) and  gnomoerotic  (narrative). [ 3 ]


Since its inception, the concept of "love maps", applied to  interpersonal relationships , has found some acceptance and is frequently referenced in books about love and sexuality. [ citation needed ]   Glenn Wilson  and Chris McLaughlin discussed it in their 2001 book  The Science of Love . [ 4 ]


Money describes the formation of an individual's lovemap as similar to the acquisition of a native language, in that it becomes established at an early age [ 5 ]  and bears the mark of the person's unique individuality, like an accent in a spoken language. [ 6 ]  According to Money, lovemaps are not present at birth, but begin to develop shortly thereafter, and manifest in full after puberty. [ 7 ]  The individual may not discover certain aspects of their lovemap until triggered by a relevant experience (such as pornography use) later in life. [ 8 ]


Psychologist Gregory Lehne states that lovemaps may be influenced by genetic or prenatal factors, but that their specific content must come from the senses. [ 9 ]  Lehne says that some perceptions are encoded in the person's lovemap after becoming sexualized for uncertain reasons, possibly because of their  associations  with provoked or random  autonomic   arousal ,  sexual arousal , or hormonal fluctuations. [ 9 ]  These associations typically form during experiences before the age of eight, Money proposes. [ 10 ] [ 6 ]  As an example, Lehne argues that a child who accidentally becomes sexually aroused during  spanking  may go on to develop an interest in  erotic spanking . [ 10 ]  Once formed, the lovemap is extremely difficult to alter. [ 6 ]


A lovemap is usually quite specific as to details of the physiognomy, build, race, color, temperament, and manner of the ideal lover. [ 6 ]  Money suggests that love is like an  inkblot test , where pair-bonding occurs if projections (shaped by a person's lovemap) on the other are mutual, typically in a courtship phase of mating. [ 11 ]


Money analyzed a large range of sexual predilections and behaviors using his model of the "lovemap".  In his book on the subject, some of the most notable concepts include: [ 12 ]


Nocturnal clitoral tumescence  ( NCT ), colloquially known as  morning bean , [ 1 ]  is a spontaneous  swelling of the clitoris  during sleep or when waking up. Similar to the process in males,  nocturnal penile tumescence , females experience clitoris tumescence and engorgement of the vagina, mainly during the  REM sleep  phase. [ 2 ]


According to Fisher et al., the increase in vaginal blood flow associated with NCT during REM sleep is similar to the process in men in frequency, i.e. 95% of REM phases. It does occur a bit more often in non-REM sleep, and each episode appears shorter in duration. In terms of size, NCT is similar to that induced by erotic stimulation when awake. The erection may be associated with erotic dreams and even, occasionally,  sleep orgasms . [ 3 ]  The phenomenon was first documented in 1970 by Karacan et al., [ 4 ]  with a single aforementioned follow-up study in 1983 by Fisher et al. [ 3 ]  More recent research includes a 2023 study by Gören et al., who found that their subjects displayed vaginal pH changes at different periods throughout the night. The study did not measure specific sleep phases. Increases in vaginal pH are associated with sexual arousal and clitoral erection.  Bartholin's glands  secrete alkaline fluid to lubricate the vagina during arousal, increasing vaginal pH. [ 5 ]


Persistent genital arousal disorder  ( PGAD ), originally called  persistent sexual arousal syndrome  ( PSAS ), [ 1 ]  is spontaneous, persistent, unwanted and uncontrollable  genital arousal  in the absence of  sexual stimulation  or  sexual desire , [ 2 ] [ 3 ]  and is typically not relieved by  orgasm . [ 3 ] [ 4 ]  Instead, multiple orgasms over hours or days may be required for relief. [ 4 ]


PGAD occurs in people of both sexes. [ 5 ] [ 4 ] [ 6 ]  It has been compared to  priapism  in male and female genitalia. [ 6 ] [ 7 ]  PGAD is rare and is not well understood. [ 2 ] [ 4 ]  The literature is inconsistent with the nomenclature. It is distinguished from  hypersexuality , which is characterized as heightened sexual desire. [ 1 ] [ 4 ]