Is it normal to not experience sexual arousal?
Nudity
In general and across cultures, public indications of sexual arousal are commonly regarded as embarrassing, both to the person aroused and the onlooker, and for this reason those parts of the human body that would indicate arousal are normally covered. Arousal is most evidently indicated by the sex organs and women's breasts, which are routinely covered, even when other parts of the body may be freely uncovered. Yet the nudity taboo may have meanings deeper than the immediate possibility of sexual arousal, for example, in the cumulative weight of tradition and habit. Clothing also expresses and symbolizes authority, and more general norms and values besides those of a sexual nature.
Human sexual response cycle
Among both sexes, the excitement phase results in an increase in heart rate, breathing rate, and a rise in blood pressure. 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. 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.
Rape of males
A common societal belief is that a male must be aroused if he gets an erection or has an orgasm, therefore that means that they are willing and enjoying any sexual activity. Roy J. Levin and Willy Van Berlo wrote in an article in the Journal of Clinical Forensic Medicine that slight genital stimulation or stress can create erections "even though no specific sexual stimulation is present". An erection does not mean that the men consent to sex. Males can get erections even in traumatic or painful sexual situations, and this does not indicate consent.
Questioning (sexuality and gender)
The American Psychological Association states:Adolescence can be a period of experimentation, and many youths may question their sexual feelings. Becoming aware of sexual feelings is a normal developmental task of adolescence. Sometimes adolescents have same-sex feelings or experiences that cause confusion about their sexual orientation. This confusion appears to decline over time, with different outcomes for different individuals.Gender, sexual orientation or sexuality does not always coincide with each other; meaning for example, if an individual identifies themselves as a heterosexual, they may not only be attracted to someone of the opposite sex and have sexual interactions with someone who is of the same sex without necessarily identifying themselves as bisexual. The importance in understanding that one does not need to apply any type of gender or sexuality label to oneself is more publicly and socially promoted in the modern day, along with gender and sexual fluidity, which is also more openly discussed and widely accepted in today's society. The individuals who do not identify themselves as either male, female, transgender, heterosexual, homosexual, bisexual or feel their sexuality is fluid, refer to themselves as gender neutral, genderqueer or agender.
Sexually induced sneezing
Sexually induced sneezing is a phenomenon characterized by sneezing during orgasm or sexual arousal.
The person experiences sneezing as a result of sexual thoughts, arousal, intercourse, or orgasm.
Sexual Desire (book)
Arousal is defined by Scruton as the state of mind in which "the body of one person awakens to the presence or thought of another." He maintains that sensations only qualify as sexual pleasure when they are "an integral part of sexual arousal." According to Scruton, it is arousal that transforms pleasurable sensations into sexual pleasure, which is characterised by intentionality. Scruton criticises views about sexual arousal expressed by authors such as Sigmund Freud, the founder of psychoanalysis, and the biologist Alfred Kinsey. He refers to the Kinsey Reports as "exercises in reduction" because of their representation of sexual arousal as a bodily state, common to humans and non-human animals, which "so irritates those subject to it that they can find relief only in the sexual act" and whose "root phenomena" are "the erection of the penis or the softening of the vagina". He maintains that Freud's theory of the erotogenic zones paradoxically presents "the localised pleasures of the sexual act as the aim or object of desire", which in his view ignores both "the drama of sexual feeling" and "the fact of the other who is desired."
Orgasm
There have been very few studies correlating orgasm and brain activity in real time. One study examined 12 healthy women using a positron emission tomography (PET) scanner while they were being stimulated by their partners. Brain changes were observed and compared between states of rest, sexual stimulation, faked orgasm, and actual orgasm. Differences were reported in the brains of men and women during stimulation. However, changes in brain activity were observed in both sexes in which the brain regions associated with behavioral control, fear and anxiety shut down. Regarding these changes, Gert Holstege said in an interview with "The Times", "What this means is that deactivation, letting go of all fear and anxiety, might be the most important thing, even necessary, to have an orgasm."
Erection
Erection is a common indicator of sexual arousal and is required for a male to effect vaginal penetration and sexual intercourse.
Sexual desire and intimate relationships
Female sexual desire is more dependent on subjective sexual excitement toward particular stimuli as opposed to an association with objective vasocongestion. Spontaneous desire refers to “spontaneous sexual wanting”, and is characterized by the need to experience sexual arousal through partnered sex, self-stimulation or fantasy, in order to experience pleasure and experience the benefits generated by the stimulation. Androgens, dopamine, oxytocin and centrally acting noradrenaline all influence spontaneous desire by motivating the pursuit of sexual stimuli and promoting increased arousability.
Sexual arousal
While there is disagreement among neurologists on whether or not it is possible to categorically distinguish male brains and female brains by measuring many variables in the brain, neurologists agree that all single variables in the brain display more individual variation and overlap between the sexes than differences between the sexes. For instance, men and women alike are capable of classifying sex acts as sexual no matter if they find them appealing or not, making a genital response to unappealing erotic stimuli a single mechanism step. It is therefore argued by neurologists that category specificity of genital response to erotical imagery, being determined by one or a small number of closely linked brain mechanisms and therefore not subject to significant multivariate effects, cannot be subject to such a large sex difference as that apparent in pletysmographic studies. These neurologists cite the existence of significant volunteering bias among men but not women in erotica research, in particular that the overrepresentation of erectile dysfunction yet underrepresentation of sexuality-related shame in volunteers is consistent with the hypothesis that genital response to both sexual relevance and appeal allows for a stronger erectile function than response only to appeal and that a majority of the male population are ashamed of their responses to unappealing stimuli, accounting for the discrepancy between the report from most heterosexual couples that male erection is faster than female lubrication and the appearance on pletysmography volunteers that female lubrication is at least as fast as male erection. They also argue that the appearance of a greater individual variability in female genital response than in male genital response is consistent with a representative female sample and a male sample subject to bias that leaves much of the individual variability unstudied, with a reference to the neurological observation that all brain structures display significant individual variability in both sexes and that no[ brain structure is variable only in females and not in males.
Erotic sexual denial
If orgasm still occurs after removal of stimulation, it typically brings less pleasure than usual, and is considered a "ruined orgasm", as opposed to being a "denied orgasm" (sometimes known in men as "blue balls"). Alternatively (for men), the release of semen during the emission phase of ejaculation might be prevented by some sort of constriction ("blocked orgasm"). Depending on the relationship, subjects might be repeatedly teased to the point of orgasm several times, but without actual orgasm, causing feelings of intense arousal and psychological need.
Sexual stimulation
The human sexual response is a dynamic combination of cognitive, emotional, and physiological processes. Whilst the most common forms of sexual stimulation discussed are fantasy or physical stimulation of the genitals and other erogenous areas, sexual arousal may also be mediated through alternative routes such as visual, olfactory and auditory means.
Sexual tension
Sexual tension is a social phenomenon that occurs when two individuals interact and one or both feel sexual desire, but the consummation is postponed or never happens. A common scenario is where the two individuals function in close proximity, such as co-workers or in a group of friends, but do not have sex to avoid awkwardness or for other reasons. Sexual tension doesn't have anything to do with the actual act of sex but is everything that leads up to it.
Being and Nothingness
Even in sex (perhaps especially in sex), men and women are haunted by a state in which consciousness and bodily being would be in perfect harmony, with desire satisfied. Such a state, however, can never be. We try to bring the beloved's consciousness to the surface of their body by use of magical acts performed, gestures (kisses, desires, etc.), but at the moment of orgasm the illusion is ended and we return to ourselves, just as it is ended when the skier comes to the foot of the mountain or when the commodity that once we desired loses its glow upon our purchase of it. There will be, for Sartre, no such moment of completion because "man is a useless passion" to be the "ens causa sui", the God of the ontological proof.
Misattribution of arousal
An example of the possible effects of misattribution of arousal is perceiving a potential partner as more attractive because of a heightened state of physiological stress. A study done by White et al. (1981) investigated this phenomenon and found that those in an unrelated aroused state will rate an attractive confederate more highly than a rater without arousal. The researchers also found that aroused raters would dislike an unattractive confederate more than those without arousal.
Arousal
Eysenck's theory of arousal describes the different natural frequency or arousal states of the brains of people who are introverted versus people who are extroverted. The theory states that the brains of extroverts are naturally less stimulated, so these types have a predisposition to seek out situations and partake in behaviors that will stimulate arousal. Whereas extroverts are naturally under-stimulated and therefore actively engage in arousing situations, introverts are naturally over-stimulated and therefore avoid intense arousal. Campbell and Hawley (1982) studied the differences in introverts versus extroverts responses to particular work environments in the library. The study found that introverts were more likely to choose quiet areas with minimal to no noise or people. Extroverts were more likely to choose areas with much activity with more noise and people. Daoussiss and McKelvie's (1986) research showed that introverts performed worse on memory tasks when they were in the presence of music compared to silence. Extroverts were less affected by the presence of music. Similarly, Belojevic, Slepcevic and Jokovljevic (2001) found that introverts had more concentration problems and fatigue in their mental processing when work was coupled with external noise or distracting factors. The level of arousal surrounding the individuals greatly affected their ability to perform tasks and behaviors, with the introverts being more affected than the extroverts, because of each's naturally high and low levels of stimulation, respectively.
Sexual assault
While sexual assault, including rape, can result in physical trauma, many people who experience sexual assault will not suffer any physical injury. Rape myths suggest that the stereotypical victim of sexual violence is a bruised and battered young woman. The central issue in many cases of rape or other sexual assault is whether or not both parties consented to the sexual activity or whether or not both parties had the capacity to do so. Thus, physical force resulting in visible physical injury is not always seen. This stereotype can be damaging because people who have experienced sexual assault but have no physical trauma may be less inclined to report to the authorities or to seek health care. However, women who experienced rape or physical violence by a partner were more likely than people who had not experienced this violence to report frequent headaches, chronic pain, difficulty sleeping, activity limitation, poor physical health, and poor mental health.
Affect display
Arousal is a basic physiological response to the presentation of stimuli. When this occurs, a non-conscious affective process takes the form of two control mechanisms; one mobilization, and the other immobilization. Within the human brain, the amygdala regulates an instinctual reaction initiating this arousal process, either freezing the individual or accelerating mobilization.
Anorgasmia
Anorgasmia, or Coughlan's syndrome, is a type of sexual dysfunction in which a person cannot achieve orgasm despite adequate stimulation. In males, it is most closely associated with delayed ejaculation. Anorgasmia can often cause sexual frustration. Anorgasmia is far more common in females (4.7 percent) than in males and is especially rare in younger men. The problem is greater in women who are post-menopause.
Sexual arousal disorder
Sexual arousal disorder is characterized by a lack or absence of sexual fantasies and desire for sexual activity in a situation that would normally produce sexual arousal, or the inability to attain or maintain typical responses to sexual arousal. The disorder is found in the DSM-IV. The condition should not be confused with a sexual desire disorder.
Sexual headache
For some patients, the headaches may be related to general exertion. About 40% of patients with sexual headaches in one study also experienced headaches from non-sexual exertion. A pressor response to exercise has been suggested as a mechanism. For other patients, the pain appears to be specifically activated by sexual excitement and contraction of facial and neck muscles.
Anal sex
While anal sex is commonly associated with male homosexuality, research shows that not all gay males engage in anal sex and that it is not uncommon in heterosexual relationships. Types of anal sex can also be a part of lesbian sexual practices. People may experience pleasure from anal sex by stimulation of the anal nerve endings, and orgasm may be achieved through anal penetration – by indirect stimulation of the prostate in men, indirect stimulation of the clitoris or an area of the vagina (sometimes called "the G-spot") in women, and other sensory nerves (especially the pudendal nerve). However, people may also find anal sex painful, sometimes extremely so, which may be primarily due to psychological factors in some cases.
Sexual arousal
Psychological sexual arousal involves appraisal and evaluation of a stimulus, categorization of a stimulus as sexual, and an affective response. The combination of cognitive and physiological states elicits psychological sexual arousal. Some suggest that psychological sexual arousal results from an interaction of cognitive and experiential factors, such as affective state, previous experience, and current social context.
Vaginal disease
Persistent genital arousal disorder (PGAD), which results in a spontaneous, persistent, and uncontrollable genital arousal, with or without orgasm, unrelated to any feelings of sexual desire. Because PGAD is relatively rare and, as its own concept apart from clitoral priapism (a rare, potentially painful medical condition in which, for an unusually extended period of time, the erect clitoris does not return to its relaxed state), has only been researched since 2001, there is little research into what may cure or remedy the disorder. In some recorded cases, PGAD was caused by, or caused, a pelvic arterial-venous malformation with arterial branches to the clitoris; surgical treatment was effective in these cases.Most vaginal discharges occur due to normal bodily functions, such as menstruation or sexual arousal (vaginal lubrication). Abnormal discharges, however, can indicate disease. Normal vaginal discharges include blood or menses (from the uterus), the most common, and clear fluid either as a result of sexual arousal or secretions from the cervix. Other non-infective causes include dermatitis. Non-sexually transmitted discharges occur from bacterial vaginosis, aerobic vaginitis and thrush or candidiasis. The final group of discharges include the sexually transmitted diseases gonorrhea, chlamydia, and trichomoniasis. The discharge from thrush is slightly pungent and white, that from trichomoniasis more foul and greenish, and that from foreign bodies resembling the discharge of gonorrhea, greyish or yellow and purulent (pus-like).
Sexual arousal
There are several informalities, terms and phrases to describe sexual arousal including "horny", "turned on", "randy", "steamy", and "lustful". Things that precipitate human sexual arousal are called erotic stimuli and colloquially known as turn-ons.
Nudity and sexuality
Sexual arousal is an aspect of a person's sexuality and a part of sexual excitement. It is accompanied by physiological changes in the aroused person. It is difficult for males to conceal full sexual arousal, or indeed lack of it, while fully nude. Penile erection is an obvious indicator of sexual excitement of a male. In the case of females, physiological changes — such as vaginal lubrication and swelling, coloring and engorgement of the labia and clitoris — are less visible to others.
Sexual arousal
Various hypotheses and theories have been propounded in order to establish the biological bases for sexual arousal in humans. Ivan Tarkhanov showed, in experiments on cutting and artificial emptying of the seminal vesicles, that the latter played the crucial role in the generation of sexual excitement in frogs. Proceeding from these experimental results, Tarkhanov put forward a hypothesis that filling and evacuation of the seminal vesicles were the main biological cause which led to sexual arousal and its disappearance in mammals and humans. Ever since Tarkhanov’s findings demonstrated sexual arousal in frogs to result from the state of seminal vesicles, the attempted elucidation of their role in other animals' sexual behaviour has been the object of experimental effort. No generalisation has yet appeared, however. The study performed by Beach & Wilson (University of California, Berkeley) in 1964 discovered that these glands do not participate in the regulation of sexual arousal of male rats in the similar manner. Whether the regularity observed in frogs is applicable to humans remains unknown. Unambiguous experimental evidence for the existence of the Tarkhanov regularity in human sexual behaviour has never been obtained.
André-Joseph Léonard
"Homosexuality is not the same as normal sex in the same way that anorexia is not a normal appetite," Léonard said in an interview for a Belgian television station. He added that he would "never call anorexia patients abnormal."
Sexual intercourse
Anorgasmia is regular difficulty reaching orgasm after ample sexual stimulation, causing personal distress. This is significantly more common in women than in men, which has been attributed to the lack of sex education with regard to women's bodies, especially in sex-negative cultures, such as clitoral stimulation usually being key for women to orgasm. The physical structure of coitus favors penile stimulation over clitoral stimulation; the location of the clitoris then usually necessitates manual or oral stimulation in order for the woman to achieve orgasm. Approximately 25% of women report difficulties with orgasm, 10% of women have never had an orgasm, and 40% or 40–50% have either complained about sexual dissatisfaction or experienced difficulty becoming sexually aroused at some point in their lives.
Human sexual activity
Sexual dysfunction is the inability to react emotionally or physically to sexual stimulation in a way projected of the average healthy person; it can affect different stages in the sexual response cycles, which are desire, excitement and orgasm. In the media, sexual dysfunction is often associated with men, but in actuality, it is more commonly observed in females (43 percent) than males (31 percent).
Fake orgasm
Orgasm is not always achieved easily during sexual activity. For both sexes, the condition of being unable to orgasm during sex is called anorgasmia; it can be caused by a variety of factors, including factors in one's life such as stress, anxiety, depression, or fatigue, as well as factors related to the sex itself; including worry, guilt, fear of painful intercourse, fear of pregnancy, the undesirability of a partner, and the undesirability of a setting. It can also be caused by drug use, including alcohol and other substances, or side effects from prescription drugs.
Sexual desire and intimate relationships
Enhanced focus, concern and attention toward the desired other has not only been associated with increased arousal by means of testosterone, but also with elevated concentrations of central dopamine and norepinephrine, and decreased levels of central serotonin. Other forms of physiological arousal associated with enhanced levels of dopamine include increased energy, exhilaration, euphoria, sleeplessness, loss of appetite, trembling, pounding heartbeat, and accelerated breathing. This same increased arousal is also a feature of attraction, and is the suggested cause of feelings of exhilaration, ecstasy, intrusive thinking about the love object, regarding them as unique and a craving for emotional union with this partner or potential partner. Feelings of anxiety, panic and fear in the presence of a beloved may also occur, as well as susceptibility to abrupt mood swings. If a relationship should suffer negatively, this may cause the attracted individual to fall into feelings of despair and brooding, which could translate to behaviours and situations outside of the relationship.
Female sexual arousal disorder
One problem with the current definition in the DSM-IV is that subjective arousal is not included. There is often no correlation between women's subjective and physiological arousal. With this in mind, recently, FSAD has been divided up into sub-types: 
The third sub-type is the most common in clinical settings
Orgasm
An empirical study carried out in 2008 provides evidence for Freud's implied link between inability to have a vaginal orgasm and psychosexual immaturity. In the study, women reported their past month frequency of different sexual behaviors and corresponding orgasm rates and completed the Defense Style Questionnaire (DSQ-40), which is associated with various psychopathologies. The study concluded that a "vaginal orgasm was associated with less somatization, dissociation, displacement, autistic fantasy, devaluation, and isolation of affect." Moreover, "vaginally anorgasmic women had immature defenses scores comparable to those of established (depression, social anxiety disorder, panic disorder, and obsessive–compulsive disorder) outpatient psychiatric groups." In the study, a vaginal orgasm (as opposed to a clitoral orgasm) was defined as being triggered solely by penile–vaginal intercourse. According to Wilhelm Reich, the lack of women's capacity to have a vaginal orgasm is due to a lack of orgastic potency, which he believed to be the result of culture's suppression of genital sexuality.
Hypoactive sexual desire disorder
In the DSM-5, male hypoactive sexual desire disorder is characterized by "persistently or recurrently deficient (or absent) sexual/erotic thoughts or fantasies and desire for sexual activity", as judged by a clinician with consideration for the patient's age and cultural context. Female sexual interest/arousal disorder is defined as a "lack of, or significantly reduced, sexual interest/arousal", manifesting as at least three of the following symptoms: no or little interest in sexual activity, no or few sexual thoughts, no or few attempts to initiate sexual activity or respond to partner's initiation, no or little sexual pleasure/excitement in 75–100% of sexual experiences, no or little sexual interest in internal or external erotic stimuli, and no or few genital/nongenital sensations in 75–100% of sexual experiences.
Sexual arousal
Sexual arousal has several stages and may not lead to any actual sexual activity, beyond a mental arousal and the physiological changes that accompany it. Given sufficient sexual stimulation, sexual arousal in humans reaches its climax during an orgasm. It may also be pursued for its own sake, even in the absence of an orgasm.
Excitation-transfer theory
Most people probably do not consider arousal from media exposure to be pronounced enough to warrant any attention, and hence they do not expect it to affect their behavior. Dismissing such arousals as trivial, the individual will tend to attribute any accumulating residues not to the preceding communication events [which are, in this instance, mediated messages] but to the new stimulus situations in which he finds himself. Moreover, by virtue of their very "unreal" and symbolic (possibly-fantasy encouraging) content, communication messages are generally not related to the person's real and immediate problems and concerns. This should further encourage misattribution of accruing arousal and hence make the person all the more vulnerable to transfer effects in his postcommunication behavior. (p. 187)
In short, stimuli, whether they be in real-life, on a television or movie screen, or a combination of the two, can elicit excitation-transfers. Today, excitation-transfer theory remains a key component of the theoretical framework of studies focusing on communication and emotion.
Sexual arousal
The relationship between sexual desire and arousal in men is complex, with a wide range of factors increasing or decreasing sexual arousal. Physiological responses, such as heart rate, blood pressure, and erection, are often discordant with self-reported subjective perceptions of arousal. This inconsistency suggests that psychological, or cognitive aspects, also have a strong effect on sexual arousal. The cognitive aspects of sexual arousal in men are not completely known, but it does involve the appraisal and evaluation of the stimulus, categorization of the stimulus as sexual, and an affective response. Research suggests that cognitive factors, such as sexual motivation, perceived gender role expectations, and sexual attitudes, contribute to sex differences observed in subjective sexual arousal. Specifically, while watching heterosexual erotic videos, men are more influenced by the sex of the actors portrayed in the stimulus, and men may be more likely than women to objectify the actors. There are reported differences in brain activation to sexual stimuli, with men showing higher levels of amygdala and hypothalamic responses than women. This suggests the amygdala plays a critical role in the processing of sexually arousing visual stimuli in men.
Sexual arousal
While young women may become sexually aroused quite easily, and reach orgasm relatively quickly with the right stimulation in the right circumstances, there are physical and psychological changes to women's sexual arousal and responses as they age. Older women produce less vaginal lubrication and studies have investigated changes to degrees of satisfaction, frequency of sexual activity, to desire, sexual thoughts and fantasies, sexual arousal, beliefs about and attitudes to sex, pain, and the ability to reach orgasm in women in their 40s and after menopause. Other factors have also been studied including socio-demographic variables, health, psychological variables, partner variables such as their partner's health or sexual problems, and lifestyle variables. It appears that these other factors often have a greater impact on women's sexual functioning than their menopausal status. It is therefore seen as important always to understand the "context of women's lives" when studying their sexuality.
Rape of males
Much like female erectile response, male erectile response is involuntary, meaning that a man need not be aroused for his penis to become erect; mechanical stimulation is all that is necessary. Arousal and stimulation are distinct things. Stimulation is a physical response to a stimulus. Men can be physically stimulated without feeling aroused and thus causing an erection. Men can be scared and intimidated into an erection, especially if the person is older or an authority.
Female hysteria
Female hysteria was once a common medical diagnosis for women. It is no longer recognized by medical authorities as a medical disorder, but still has lasting social implications. Its diagnosis and treatment were routine for hundreds of years in Western Europe. In Western medicine hysteria was considered both common and chronic among women. The American Psychiatric Association dropped the term "hysteria" in 1952. Even though it was categorized as a disease, hysteria's symptoms were synonymous with normal functioning female sexuality. Women considered to have it exhibited a wide array of symptoms, including anxiety, shortness of breath, fainting, nervousness, sexual desire, insomnia, fluid retention, heaviness in the abdomen, irritability, loss of appetite for food or sex, (paradoxically) sexually forward behaviour, and a "tendency to cause trouble for others". In extreme cases, the woman may have been forced to enter an insane asylum or to have undergone surgical hysterectomy.
Female hysteria
According to Pierre Roussel and Jean-Jacques Rousseau, femininity is a natural and essential desire for women, 'Femininity is for both authors an essential nature, with defined functions, and the disease is explained by the non-fulfillment of natural desire.' It is during this era of industrial revolution and the major development of cities and modern life, that this natural tendency is thought to be disrupted causing lethargy or melancholy leading to hysteria. This melancholy or lethargy is retrospectively thought to have been caused and aggravated by the restrictive views on female sexuality at the time, which held masturbation as something unhealthy and unchaste. This led to a surge in female patients for medical practitioners who were looking for the massage cure to their hysteria. The rate of hysteria was so high in the socially restrictive industrial era that women were prone to carrying smelling salts about their person in case they swooned, reminiscent of Hippocrates' theory of smells coercing the uterus back into place. For doctors manual massage treatment was becoming tiring, laborious and time-consuming and they were looking for a way to increase productivity.
Orgasm
There is some debate whether certain types of sexual sensations should be accurately classified as orgasms, including female orgasms caused by G-spot stimulation alone, and the demonstration of extended or continuous orgasms lasting several minutes or even an hour. The question centers around the clinical definition of orgasm, but this way of viewing orgasm is merely physiological, while there are also psychological, endocrinological, and neurological definitions of orgasm. In these and similar cases, the sensations experienced are subjective and do not necessarily involve the involuntary contractions characteristic of orgasm. However, the sensations in both sexes are extremely pleasurable and are often felt throughout the body, causing a mental state that is often described as transcendental, and with vasocongestion and associated pleasure comparable to that of a full-contractionary orgasm. For example, modern findings support distinction between ejaculation and male orgasm. For this reason, there are views on both sides as to whether these can be accurately defined as orgasms.
Orgasm
The inability to have orgasm, or regular difficulty reaching orgasm after ample sexual stimulation, is called anorgasmia or inorgasmia. If a male experiences erection and ejaculation but no orgasm, he is said to have sexual anhedonia (a condition in which an individual cannot feel pleasure from an orgasm) or ejaculatory anhedonia. Anorgasmia is significantly more common in women than in men, which has been attributed to the lack of sex education with regard to women's bodies, especially in sex-negative cultures, such as clitoral stimulation usually being key for women to orgasm.
Masturbation
The medical consensus is that masturbation is a medically healthy and psychologically normal habit. According to the Merck Manual of Diagnosis and Therapy, "It is considered abnormal only when it inhibits partner-oriented behavior, is done in public, or is sufficiently compulsive to cause distress."
Misattribution of arousal
Misattribution of arousal is a term in psychology which describes the process whereby people make a mistake in assuming what is causing them to feel aroused. For example, when actually experiencing physiological responses related to fear, people mislabel those responses as romantic arousal. The reason physiological symptoms may be attributed to incorrect stimuli is because many stimuli have similar physiological symptoms such as increased blood pressure or shortness of breath.
Anorgasmia
Primary anorgasmia is a condition where one has never experienced an orgasm. This is significantly more common in women, although it can occur in men who lack the gladipudendal (bulbocavernosus) reflex. Women with this condition can sometimes achieve a relatively low level of sexual excitement. Frustration, restlessness, and pelvic pain or a heavy pelvic sensation may occur because of vascular engorgement. On occasion, there may be no obvious reason why orgasm is unobtainable. In such cases, women report that they are unable to orgasm even if they have a caring, skilled partner, adequate time and privacy, and an absence of medical issues which would affect sexual satisfaction.
Sexual stimulation
Sexual arousal includes feelings, attractions and desires, as well as physiological changes. These can be elicited not only by physical but also mental stimulations, such as fantasy, erotic literature, dreams, role-play, and imagination.
Sexual fantasy is a form of mental sexual stimulation which many people engage in. It is where a person imagines a sexual experience while they are awake. Fantasy has less social or safety limits than in real life situations. It gives people more freedom to experiment or think of things they could not necessarily try in real life and can be anything from imagining your spouse naked, to imagining a sexual experience with a mythical creature. Common sexual fantasies include imagining activities with a loved partner, reliving past experiences and experiences with multiple partners of the opposite gender. It's also common to have fantasies about things you would not do in real life and about taboo or illegal activities, such as forcing another, or being forced to have sex, intercourse with a stranger and sex with a boy or girl or older partner.
Sexual arousal
Regardless of the difference in these two questionnaires, both surveys' scores show normal distribution verifying the hypothesis that there is a normal individual variation in sexual arousal and inhibition. In the original SIS/SES questionnaire, statistically significant gender differences are seen despite considerable overlap in scores between men and women. On average, males score higher on sexual excitation and lower than females on both facets of sexual inhibition. As of yet, the differences in scores between genders have not been explained beyond the theoretical level. 
The source of individual variability on the sexual excitation and inhibition systems is not known definitively. Even less is known about how these systems develop in individuals. Age of first masturbation has been used as a measure to assess sexual development. Age of masturbatory onset is much more variable in girls than boys, whose tend to be close to puberty. Researchers have not determined whether this gender difference is biological in nature or influenced by sociocultural values. One twin-study has found evidence for the heritability of both factors of SIS, but research suggests that SES variability is down to environmental factors.
Female sexual arousal disorder
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.
Foreplay
Sexual desire is an aspect of a person's sexuality, which varies from one person to another. A person who desires sexual activity with another person can attempt to provoke sexual arousal in the person. Depending on the type and intensity of the relationship between the two people, the stimuli may involve indicating to the person in some subtle and romantic way that he or she has that desire or by provoking other erotic stimuli. There are many potential stimuli, both physical and mental, which can cause a person to become sexually aroused, and which stimuli are invoked will depend on circumstances at a particular time.
Sexual dysfunction
Orgasm disorders, specifically anorgasmia, present as persistent delays or absence of orgasm following a normal sexual excitement phase in at least 75% of sexual encounters. The disorder can have physical, psychological, or pharmacological origins. SSRI antidepressants are a common pharmaceutical culprit, as they can delay orgasm or eliminate it entirely. A common physiological culprit of anorgasmia is menopause, where one in three women report problems obtaining an orgasm during sexual stimulation following menopause.
Hypoactive sexual desire disorder
The DSM-5, published in 2013, split HSDD into "male hypoactive sexual desire disorder" and "female sexual interest/arousal disorder". The distinction was made because men report more intense and frequent sexual desire than women. According to Lori Brotto, this classification is desirable compared to the DSM-IV classification system because: (1) it reflects the finding that desire and arousal tend to overlap (2) it differentiates between women who lack desire before the onset of activity, but who are receptive to initiation and or initiate sexual activity for reasons other than desire, and women who never experience sexual arousal (3) it takes the variability in sexual desire into account. Furthermore, the criterion of 6 symptoms be present for a diagnosis helps safeguard against pathologizing adaptive decreases in desire.
Chemical castration
Some neurologists acknowledge that testosterone plays a role in sexual arousal but that reducing sex drive will likely not reduce inappropriate sex behaviour. These researchers argue that since a weaker internal signal in the brain means a higher requirement for external stimulation to create a feedback loop that tires the brain circuits out as in orgasm and lead to satisfaction, a reduction of the internal stimulation from hormones would make the required external stimulation stronger and also more specific, as weaker signals involve narrower ranges of other brain functions in their loops. These scientists therefore argue that the biological (as opposed to sociological) effect of reduced testosterone is to make it more difficult and not easier to use masturbation without pornography or other socially acceptable substitutes to manage remaining sex drive in a former offender, and that many community persons (both male and female) find that a lower initial arousal makes it more difficult to orgasm by masturbation without pornography or with non-preferred stimulation.
Anxiety disorder
Sexual dysfunction often accompanies anxiety disorders, although it is difficult to determine whether anxiety causes the sexual dysfunction or whether they arise from a common cause. The most common manifestations in individuals with anxiety disorder are avoidance of intercourse, premature ejaculation or erectile dysfunction among men and pain during intercourse among women. Sexual dysfunction is particularly common among people affected by panic disorder (who may fear that a panic attack will occur during sexual arousal) and posttraumatic stress disorder.
Orgasm
Orgasms may thus occur as the result of sexual assault or rape. An involuntary orgasm from forced sexual contact often results in feelings of shame caused by internalization of victim-blaming attitudes. The incidence of those who experience unsolicited sexual contact and experience orgasm is very low, though possibly under-reported due to shame or embarrassment; such orgasms additionally happen regardless of gender.
Sexual arousal
In 2000, Rosemary Basson presented an alternative model to the human sexual response cycle that is "specific to women’s sexual response". She argues that gender differences in sex drive, sexual motivation, sexual concordance, and capacity for orgasm underlie the need for an alternative model of sexual response. While the human sexual response cycle begins with desire, followed by arousal, orgasm, and finally resolution, Basson’s alternative model is circular and begins with women feeling a need for intimacy, which leads her to seek out and be receptive to sexual stimuli; women then feel sexual arousal, in addition to sexual desire. The cycle results in an enhanced feeling of intimacy. Basson emphasizes the idea that a lack of spontaneous desire should not be taken as an indication of female sexual dysfunction; many women experience sexual arousal and responsive desire simultaneously when they are engaged in sexual activity.
Human sexual response cycle
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, petting, or viewing erotic images, that leads to sexual arousal. During this stage, the body prepares for sexual intercourse, initially leading to the plateau phase. There is wide socio-cultural variation regarding preferences for the length of foreplay and the stimulation methods used. Physical and emotional interaction and stimulation of the erogenous zones during foreplay usually establishes at least some initial arousal.
Asexuality
Asexual people, though lacking sexual attraction to any gender, might engage in purely romantic relationships, while others might not. There are asexual-identified individuals who report that they feel sexual attraction but not the inclination to act on it because they have no true desire or need to engage in sexual or non-sexual activity (cuddling, hand-holding, etc.), while other asexuals engage in cuddling or other non-sexual physical activity. Some asexuals participate in sexual activity out of curiosity. Some may masturbate as a solitary form of release, while others do not feel a need to do so.
Sexual fantasy
Unusual sexual fantasies are more common in men, with fantasies of urinating on their sexual partner and being urinated on being significantly higher among males. The Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) states that paraphilias are rarely diagnosed in women, with the exception of sexual masochism. Furthermore, sexual arousal has been found to be greater in men than in women when asked to entertain the thought of engaging in paraphilic sexual activity. It may, however, be the case that paraphilias are reported less often in women because they are under-researched in women. Paraphilic sexual fantasies in females include sexual sadism, exhibitionism, and pedophilia.
Asexuality
While some asexuals masturbate as a solitary form of release or have sex for the benefit of a romantic partner, others do not (see above). Fischer et al. reported that "scholars who study the physiology around asexuality suggest that people who are asexual are capable of genital arousal but may experience difficulty with so-called subjective arousal." This means that "while the body becomes aroused, subjectively – at the level of the mind and emotions – one does not experience arousal".
Erection
Spontaneous erection, also known as involuntary, random or unwanted erection, is commonplace and a normal part of male physiology. Socially, such erections can be embarrassing if they happen in public or when undesired. Erections can occur spontaneously at any time of day, and if clothed may cause a bulge which (if required) can be disguised or hidden by wearing close-fitting underwear, a long shirt, or baggier clothes.
Sexual arousal
However, when a person fails to be aroused in a situation that would normally produce arousal and the lack of arousal is persistent, it may be due to a sexual arousal disorder or hypoactive sexual desire disorder. There are many reasons why a person fails to be aroused, including a mental disorder, such as depression, drug use, or a medical or physical condition. The lack of sexual arousal may be due to a general lack of sexual desire or due to a lack of sexual desire for the current partner. A person may always have had no or low sexual desire or the lack of desire may have been acquired during the person's life. There are also complex philosophical and psychological issues surrounding sexuality. Attitudes towards life, death, childbirth, one's parents, friends, family, contemporary society, the human race in general, and particularly one's place in the world play a substantive role in determining how a person will respond in any given sexual situation.
Sport psychology
Although anxiety or stress are often believed to a negative thing, they are actually a necessary response for the body to survive. It is natural for the body to exhibit certain levels of anxiety and stress, however, it becomes a problem when it begins to inhibit activity. Arousal is the physiological and psychological activation of the body in response to an event. Trait anxiety exists in an individual when they experience unusually high response levels to a wide spread of situations that are not threatening. State anxiety is the momentary feeling of nervousness or worry that accompanies the arousal of the body. State anxiety can be defined cognitively, where nervous thoughts and worries occur for a moment. There is also somatic state anxiety, where the body experiences a physiological response to arousal. This sometimes manifests momentarily as a fluttering in the stomach or an elevated pulse. There are four major theories of arousal and anxiety.
Sexual arousal
Sexual arousal (also sexual excitement) is the arousal of sexual desire, during or in anticipation of sexual activity. A number of physiological responses occur in the body and mind as preparation for sexual intercourse and continue during it. Male arousal will lead to an erection, and in female arousal the body's response is engorged sexual tissues such as nipples, vulva, clitoris, vaginal walls and vaginal lubrication. Mental stimuli and physical stimuli such as touch, and the internal fluctuation of hormones, can influence sexual arousal.
Testosterone
Studies conducted in rats have indicated that their degree of sexual arousal is sensitive to reductions in testosterone. When testosterone-deprived rats were given medium levels of testosterone, their sexual behaviors (copulation, partner preference, etc.) resumed, but not when given low amounts of the same hormone. Therefore, these mammals may provide a model for studying clinical populations among humans suffering from sexual arousal deficits such as hypoactive sexual desire disorder.
Sexual arousal
Another explanation of sexual arousal is offered by the approach which Kazimierz Imieliński calls the "psychohydraulic model of sexuality." This point of view likens human sexuality to a steam boiler, with biological processes or internal irritants creating sexual tension. If the level of this tension reaches threshold, sexual arousal occurs as the expression of necessity to let off steam. Gary F. Kelly (Clarkson University) describes this model as follows:
The "psychohydraulic model of sexuality" has been formulated most definitely in psychoanalysis:
Sexual arousal
Depending on the situation, a person can be sexually aroused by a variety of factors, both physical and mental. A person may be sexually aroused by another person or by particular aspects of that person, or by a non-human object. The welcome physical stimulation of an erogenous zone or acts of foreplay can result in arousal, especially if it is accompanied with the anticipation of imminent sexual activity. Sexual arousal may be assisted by a romantic setting, music or other soothing situation. The potential stimuli for sexual arousal vary from person to person, and from one time to another, as does the level of arousal.
Expectancy violations theory
When arousal occurs, one's interest or attention to the deviation increases, resulting in less attention paid to the message and more attention to the source of the arousal. There are two kinds of arousals. Cognitive arousal is an idea that people will be mentally aware of the violation. Physical occurs when people have body actions and behaviors in response to the deviations from their expectations.
Persistent genital arousal disorder
The term "persistent sexual arousal syndrome" was coined by researchers Leiblum and Nathan in 2001. In 2006, Leiblum renamed the condition to "persistent genital arousal disorder" to indicate that genital arousal sensations are different from those that result from true sexual arousal. The rename was also considered to give the condition a better chance of being classified as a dysfunction.
Motivational intensity
Motivational intensity and arousal are related, but are considered to be separate ideas; arousal has implications for action, but motivational intensity does not and it is possible to experience high levels of arousal, but not experience motivational intensity (e.g., laughing). Gable and Harmon-Jones asked participants’ to view pictures and then complete an attention task. Half of the participants pedaled on a stationary bicycle (to induce high arousal), while others did not. Results demonstrated that there was no difference in performance on the attention task with high or low levels of arousal, but pictures high in motivational intensity narrowed attention, compared to pictures that were low in motivational intensity.
Asexuality
There is significant debate over whether or not asexuality is a sexual orientation. It has been compared and equated with hypoactive sexual desire disorder (HSDD), in that both imply a general lack of sexual attraction to anyone; HSDD has been used to medicalize asexuality, but asexuality is generally not considered a disorder or a sexual dysfunction (such as anorgasmia, anhedonia, etc.), because it does not necessarily define someone as having a medical problem or problems relating to others socially. Unlike people with HSDD, asexual people normally do not experience "marked distress" and "interpersonal difficulty" concerning feelings about their sexuality, or generally a lack of sexual arousal; asexuality is considered the lack or absence of sexual attraction as a life-enduring characteristic. One study found that, compared to HSDD subjects, asexuals reported lower levels of sexual desire, sexual experience, sex-related distress and depressive symptoms. Researchers Richards and Barker report that asexuals do not have disproportionate rates of alexithymia, depression, or personality disorders. Some people, however, may identify as asexual even if their non-sexual state is explained by one or more of the aforementioned disorders.
Sexual dysfunction
Sexual dysfunction (or sexual malfunction or sexual disorder) is difficulty experienced by an individual or a couple during any stage of a normal sexual activity, including physical pleasure, desire, preference, arousal or orgasm. According to the DSM-5, sexual dysfunction requires a person to feel extreme distress and interpersonal strain for a minimum of six months (excluding substance or medication-induced sexual dysfunction). Sexual dysfunctions can have a profound impact on an individual's perceived quality of sexual life. The term "sexual disorder" may not only refer to physical sexual dysfunction, but to paraphilias as well; this is sometimes termed "disorder of sexual preference".
Sexual arousal
After a certain time, the same process begins anew. Such an approach assumes sexual arousal to be a spontaneous desire that appears periodically like sensations of hunger and thirst. Drawing a parallel between these sensations and sexual excitation is widely accepted now: "Everyone must experience sexuality in some way to survive. ... In this sense sex is a necessity of life, just as air, food, and warmth." And yet there is no empirical evidence in support of such a parallel, Imieliński says. Sensations of hunger and thirst occur due to certain states of physiological insufficiency. The feeling of hunger results from the lack of glucose, fats and amino acids in blood. The feeling of thirst occurs in response to reduction of the water content of tissues. None of similar states of physiological deficiency responsible for the periodical appearance of sexual arousal has been revealed in human sexuality.
Sexual intercourse
Sexual intercourse or other sexual activity can encompass various sexually stimulating factors (physiological stimulation or psychological stimulation), including different sex positions or the use of sex toys. Foreplay may precede some sexual activities, often leading to sexual arousal of the partners and resulting in the erection of the penis or natural lubrication of the vagina. It is also common for people to be as sexually satisfied by being kissed, touched erotically, or held as they are by sexual intercourse.
Sexuality after spinal cord injury
The body's physical arousal response (vaginal lubrication and engorgement of the clitoris in women and erection in men) occurs due to two separate pathways which normally work together: psychogenic and reflex. Arousal due to fantasies, visual input, or other mental stimulation is a psychogenic sexual experience, and arousal resulting from physical contact to the genital area is reflexogenic. In psychogenic arousal, messages travel from the brain via the spinal cord to the nerves in the genital area. The psychogenic pathway is served by the spinal cord at levels T11–L2. Thus people injured above the level of the T11 vertebra do not usually experience psychogenic erection or vaginal lubrication, but those with an injury below T12 can. Even without these physical responses, people with SCI often feel aroused, just as uninjured people do. The ability to feel the sensation of a pinprick and light touch in the dermatomes for T11–L2 predicts how well the ability to have psychogenic arousal is preserved in both sexes. Input from the psychogenic pathway is sympathetic, and most of the time it sends inhibitory signals that prevent the physical arousal response; in response to sexual stimulation, excitatory signals are increased and inhibition is reduced. Removing the inhibition that is normally present allows the spinal reflexes that trigger the arousal response to take effect.
Sexual Desire (book)
According to Scruton, sexual desire does not originate in sexual arousal or have sexual arousal as its aim. He believes that while sexual arousal may seem to support the idea that desire is "a 'biological' fact, rooted in the life which we share with animals", it does not do so, because it is an interpersonal response founded in an epistemic intentionality and can be experienced only by people. He argues that though non-human animals experience sexual urges, they do not experience sexual desire. He attempts to defend this conclusion against potential criticism by clarifying the ideas of the animal and the person. In his view, the concept of the person is not a qualification of the concept of the animal, but a distinct concept with a differing purpose. Scruton outlines the history of the term "person", noting that in the theatre a "persona", originally a mask, came to stand for a theatrical character. "Persona" was then used in a more general sense, to refer to any representation of a human being, and in Roman law came to denote the "collection of rights and liabilities which the law courts could adjudicate, on behalf of the subject who appeared before them." Though he rejects the idea that the concept of legal personality can be used to distinguish what separates humans from non-human animals, he considers it relevant to understanding the concept of the person.
Scruton believes that desire is characterised by intentionality. He argues that "desire expresses itself through patterns of deliberate activity" but can nevertheless be understood as an expression of human mental states only if "we recognise the central importance of the involuntary aspect of human behaviour", giving blushing, laughter, and the erection of the penis as examples. He sees the focus of desire as embodiment, which entails finding a unity between the body and the personal identity of the desired person. He criticises what he considers a common picture of the aim of sexual desire, according to which it begins in sexual arousal and has as its objective "pleasurable stimulus" and orgasm. He considers Kinsey and his co-authors the "most-simple minded" proponents of this view, writing that they unacceptably see orgasm as the aim of desire and "the presence of the other person as its occasion." He follows Sartre and Thomas Nagel in holding that the "attempt to assimilate sexual desire to appetite misses the interpersonal component of human sexual responses." He argues that ordinary language shows that the object of sexual desire is the "person himself", and that despite the possibility of mistakes of identity, it is part of the directed character of desire that its object is a particular person.
Sexual stimulation
Olfactory information is critical to human sexual behavior. One study investigating olfactory sexual stimulation found that men experience sexual arousal in response to a female perfume. Individuals rated odourant stimulation and perceived sexual arousal. They also had functional MRI scans taken during the experiment. The results showed that olfactory stimulation with women's perfume produces activation of specific brain areas associated with sexual arousal in men.
Erotic plasticity
According to Meredith Chivers, straight women are physically aroused by a greater variety of erotic images than men, and this physical arousal does not match subjective arousal.
Similar results were found in a study that showed both consensual and non-consensual sex scenes to men and women. Neither men nor women reported sexual arousal to the rape scenes, but women's bodies responded in a similar way to both scenarios. The usual explanation for this is that women's physical arousal is an evolutionary automatic response, to prevent damage during rape.
However, a study that measured sexual arousal through pupil dilation found that physical response of lesbian and bisexual women to erotic images was more category-specific, with lesbian women showing more response to women, and bisexual women showing more response to the preferred sex than the other. This may be due to masculinization of the brain via prenatal hormones. The difference between straight and non-straight women was consistent with Chivers' findings.
The same study found also sexual fluidity in men's response, that moved along a continuum between heterosexuality and homosexuality.
Asexuality
With regard to sexual orientation categories, asexuality may be argued as not being a meaningful category to add to the continuum, and instead argued as the lack of a sexual orientation or sexuality. Other arguments propose that asexuality is the denial of one's natural sexuality, and that it is a disorder caused by shame of sexuality, anxiety or sexual abuse, sometimes basing this belief on asexuals who masturbate or occasionally engage in sexual activity simply to please a romantic partner. Within the context of sexual orientation identity politics, asexuality may pragmatically fulfill the political function of a sexual orientation identity category.
Human female sexuality
The stimulation of female erogenous zones, like those of a male counterpart, may result in a sexual response, the aim of which is to increase the level of arousal in order to enjoy the act and potentially reach an orgasm. The erogenous zones are different from woman to woman and it is also likely that the stimulation of the erogenous areas that some women find pleasant and exciting may be difficult to bear by others.
Libido
There is no widely accepted measure of what is a healthy level for sex desire. Some people want to have sex every day, or more than once a day; others once a year or not at all. However, a person who lacks a desire for sexual activity for some period of time may be experiencing a hypoactive sexual desire disorder or may be asexual. A sexual desire disorder is more common in women than in men. Erectile dysfunction may happen to the penis because of lack of sexual desire, but these two should not be confused. For example, large recreational doses of amphetamine or methamphetamine can simultaneously cause erectile dysfunction and significantly increase libido. However, men can also experience a decrease in their libido as they age.
Sexual arousal
Frederick Toates presented a model of sexual motivation, arousal, and behavior in 2009 that combines the principles of "incentive-motivation theory" and "hierarchical control of behavior". The of sex suggests that incentive cues in the environment invade the nervous system, which results in sexual motivation. Positive sexual experiences enhance motivation, while negative experiences reduce it. Motivation and behaviour are organized hierarchically; each are controlled by a combination direct (external stimuli) and indirect (internal cognitions) factors. Excitation and inhibition of behavior act at various levels of this hierarchical structure. For instance, an external stimulus may directly excite sexual arousal and motivation below a conscious level of awareness, while an internal cognition can elicit the same effects indirectly, through the conscious representation of a sexual image. In the case of inhibition, sexual behavior can be active or conscious (e.g., choosing not to have sex) or it can be passive or unconscious (e.g., being unable to have sex due to fear). Toates emphasizes the importance considering cognitive representations in addition to external stimuli; he suggests that mental representations of incentives are interchangeable with excitatory external stimuli for eliciting sexual arousal and motivation.
Human sexual activity
Human sexual activity, human sexual practice or human sexual behaviour is the manner in which humans experience and express their sexuality. People engage in a variety of sexual acts, ranging from activities done alone (e.g., masturbation) to acts with another person (e.g., sexual intercourse, non-penetrative sex, oral sex, etc.) in varying patterns of frequency, for a wide variety of reasons. Sexual activity usually results in sexual arousal and physiological changes in the aroused person, some of which are pronounced while others are more subtle. Sexual activity may also include conduct and activities which are intended to arouse the sexual interest of another or enhance the sex life of another, such as strategies to find or attract partners (courtship and display behaviour), or personal interactions between individuals (for instance, foreplay or BDSM). Sexual activity may follow sexual arousal.
Sexual stimulation
Physical sexual stimulation usually consists of touching the genitals or other erogenous zones. Masturbation, erotic massage, sexual intercourse, a handjob or fingering are types of physical sexual stimulation involving the genitals. Sexual arousal is usually triggered through sensitive nerves in these body parts, which cause the release of pleasure-causing chemicals (endorphins) that act as mental rewards to pursue such stimulation. A person may also become sexually aroused by touching another person's genitals or other body parts. The bulbocavernosus reflex is triggered by stimulation of the glans penis or clitoris.
Sexual desire and intimate relationships
Female arousal is complex, as evidenced by the findings that women’s reported feelings of sexual arousal have not been found to correlate with physiological genital arousal, and that for many women there is no reported distinction between their experiences of sexual desire and arousal.
Libido
The American Medical Association has estimated that several million US women suffer from a female sexual arousal disorder, though arousal is not at all synonymous with desire, so this finding is of limited relevance to the discussion of libido. Some specialists claim that women may experience low libido due to some hormonal abnormalities such as lack of luteinising hormone or androgenic hormones, although these theories are still controversial. Also, women commonly lack sexual desire in the period immediately after giving birth. Moreover, any condition affecting the genital area can make women reject the idea of having intercourse. It has been estimated that half of women experience different health problems in the area of the vagina and vulva, such as thinning, tightening, dryness or atrophy. Frustration may appear as a result of these issues and because many of them lead to painful sexual intercourse, many women prefer not having sex at all. Surgery or major health conditions such as arthritis, cancer, diabetes, high blood pressure, coronary artery disease or infertility may have the same effect in women. Surgery that affects the hormonal levels in women include oophorectomies.
Low arousal theory
A person with low arousal reacts less to stimuli than one without. This individual, according to Hare (1970) is "in a chronic state of 'stimulus-hunger'". To further explain, Mawson and Mawson (1977) claim that he or she needs more "sensory inputs" to feel normal.
Orgasm
Since ancient times in Western Europe, women could be medically diagnosed with a disorder called female hysteria, the symptoms of which included faintness, nervousness, insomnia, fluid retention, heaviness in abdomen, muscle spasm, shortness of breath, irritability, loss of appetite for food or sex, and "a tendency to cause trouble". Women considered suffering from the condition would sometimes undergo "pelvic massage" — stimulation of the genitals by the doctor until the woman experienced "hysterical paroxysm" (i.e., orgasm). Paroxysm was regarded as a medical treatment, and not a sexual release. The disorder has ceased to be recognized as a medical condition since the 1920s.
Sneeze
It is known for some people to sneeze during the initial phases of sexual arousal. Doctors suspect that the phenomenon might arise from a case of crossed wires in the autonomic nervous system, which regulates a number of functions in the body, including "waking up" the genitals during arousal. The nose, like the genitals, contains erectile tissue.. This phenomenon may prepare the vomeronasal organ for increased detection of pheromones. Sneezing while menstruating may result in a sudden vaginal menses emission.
Rape fantasy
A male sexual fantasy of raping a woman may bring sexual arousal either from imagining a scene in which first a woman objects but then comes to like and eventually participate in the intercourse, or else one in which the woman does not like it and arousal is associated with the idea of hurting the woman.
Human sexual activity
Most people engage in sexual activity because of pleasure they derive from the arousal of their sexuality, especially if they can achieve orgasm. Sexual arousal can also be experienced from foreplay and flirting, and from fetish or BDSM activities, or other erotic activities. Most commonly, people engage in sexual activity because of the sexual desire generated by a person to whom they feel sexual attraction; but they may engage in sexual activity for the physical satisfaction they achieve in the absence of attraction for another, as in the case of casual or social sex. At times, a person may engage in a sexual activity solely for the sexual pleasure of their partner, such as because of an obligation they may have to the partner or because of love, sympathy or pity they may feel for the partner.
Masturbation
Masturbation is the sexual stimulation of one's own genitals for sexual arousal or other sexual pleasure, usually to the point of orgasm. The stimulation may involve hands, fingers, everyday objects, sex toys such as vibrators, or combinations of these. Manual stimulation of a partner, such as fingering, a handjob or mutual masturbation, is a common sexual act and can be a substitute for penetration. Studies have found that masturbation is frequent in humans of both sexes and all ages, although there is variation. Various medical and psychological benefits have been attributed to a healthy attitude toward sexual activity in general and to masturbation in particular. No causal relationship is known between masturbation and any form of mental or physical disorder.
Female sexual arousal disorder
It is also worth noting that female sexual arousal disorder is rarely a solitary diagnosis. Due to its high rates of comorbidity with hypoactive sexual desire disorder, a new disorder is being proposed for the DSM-5: Sexual Interest/Arousal Disorder. The diagnostic criterion "persistent or recurrent" symptoms is also problematic in that it is vague and could lead to too much reliance on clinical judgment.
Orgasm
Approximately 25% of women report difficulties with orgasm, 10% of women have never had an orgasm, and 40% or 40–50% have either complained about sexual dissatisfaction or experienced difficulty becoming sexually aroused at some point in their lives. A 1994 study by Laumann et al. found that 75% of men and 29% of women always have orgasms with their partner. Women are much more likely to be nearly always or always orgasmic when alone than with a partner. However, in a 1996 study by Davis et al., 62% of women in a partnered relationship said they were satisfied with the frequency/consistency of their orgasms. Additionally, some women express that their most satisfying sexual experiences entail being connected to someone, rather than solely basing satisfaction on orgasm.
Parasomnia
Confusional arousal is a condition when an individual awakens from sleep and remains in a confused state. It is characterized by the individual's partial awakening and sitting up to look around. They usually remain in bed and then return to sleep. These episodes last anywhere from seconds to minutes and may not be reactive to stimuli. Confusional arousal has a prevalence of 4% in adults, and is common in children. Infants and toddlers usually experience confusional arousals beginning with large amounts of movement and moaning, which can later progress to occasional thrashings or inconsolable crying. 
Confusional arousals are not considered dangerous. Another sleeping disorder may be present triggering these incomplete arousals.
Human female sexuality
In terms of female psychological arousal, recent research by personality psychologist and biological anthropologist Gerulf Rieger in 2015 suggested that homosexual females experienced more male-typical sexual arousal to members of the same sex than heterosexual females did to members of the opposite sex, as well as being more masculine in non-sexual behaviours.
Bisexuality
Male bisexuality is particularly presumed to be non-existent, with sexual fluidity studies adding to the debate. In 2005, researchers Gerulf Rieger, Meredith L. Chivers, and J. Michael Bailey used penile plethysmography to measure the arousal of self-identified bisexual men to pornography involving only men and pornography involving only women. Participants were recruited via advertisements in gay-oriented magazines and an alternative paper. They found that the self-identified bisexual men in their sample had genital arousal patterns similar to either homosexual or heterosexual men. The authors concluded that "in terms of behavior and identity, bisexual men clearly exist", but that male bisexuality had not been shown to exist with respect to arousal or attraction. The assertion of Bailey that "for men arousal is orientation" was criticized by Fairness and Accuracy in Reporting (FAIR) as a simplification which neglects to account for behavior and self-identification. Further, some researchers hold that the technique used in the study to measure genital arousal is too crude to capture the richness (erotic sensations, affection, admiration) that constitutes sexual attraction. The National Gay and Lesbian Task Force called the study and "The New York Times" coverage of it flawed and biphobic.
Sexual stimulation
Sexual stimulation is any stimulus (including bodily contact) that leads to, enhances and maintains sexual arousal, and may lead to orgasm. Although sexual arousal may arise without physical stimulation, achieving orgasm usually requires physical sexual stimulation.
Sexual desire and intimate relationships
According to the circular response model of sexual desire, the arousal is not spontaneous, but must be triggered by specific sexual stimuli. Once the individual is aroused, intimacy motivations work in concert with this achieved arousal to promote the development of yet further sexual arousal. Previously undesirable sexual stimuli, specifically to breasts and genitalia, may be welcome and enjoyed once the development of sexual desire is fostered.
Orgasm
Orgasms can be achieved by a variety of activities, including vaginal, anal or oral sex, non-penetrative sex or masturbation. Orgasm may also be achieved by the use of a sex toy, such as a sensual vibrator or an erotic electrostimulation. It can additionally be achieved by stimulation of the nipples or other erogenous zones, though this is rarer. In addition to physical stimulation, orgasm can be achieved from psychological arousal alone, such as during dreaming (nocturnal emission for males or females) or by forced orgasm. Orgasm by psychological stimulation alone was first reported among people who had spinal cord injury. Although sexual function and sexuality after spinal cord injury is very often impacted, this injury does not deprive one of sexual feelings such as sexual arousal and erotic desires.