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. Psychologically, possible causes of the disorder include the impact of childhood and adolescence experiences and current events – both within the individual and within the current relationship.

Low sexual desire alone is not equivalent to HSDD because of the requirement in HSDD that the low sexual desire causes marked distress and interpersonal difficulty and because of the requirement that the low desire is not better accounted for by another disorder in the DSM or by a general medical problem. It is therefore difficult to say exactly what causes HSDD. It is easier to describe, instead, some of the causes of low sexual desire.

In men, though there are theoretically more types of HSDD/low sexual desire, typically men are only diagnosed with one of three subtypes.

- Lifelong/generalised: The man has little or no desire for sexual stimulation (with a partner or alone) and never had.

- Acquired/generalised: The man previously had sexual interest in his present partner, but lacks interest in sexual activity, partnered or solitary.

- Acquired/situational: The man was previously sexually interested in his present partner but now lacks sexual interest in this partner but has desire for sexual stimulation (i.e. alone or with someone other than his present partner.)

Though it can sometimes be difficult to distinguish between these types, they do not necessarily have the same cause. The cause of lifelong/generalized HSDD is unknown. In the case of acquired/generalized low sexual desire, possible causes include various medical/health problems, psychiatric problems, low levels of testosterone or high levels of prolactin. One theory suggests that sexual desire is controlled by a balance between inhibitory and excitatory factors. This is thought to be expressed via neurotransmitters in selective brain areas. A decrease in sexual desire may therefore be due to an imbalance between neurotransmitters with excitatory activity like dopamine and norepinephrine and neurotransmitters with inhibitory activity, like serotonin. The, New York-based, "New View Campaign" organization has expressed skepticism about too much emphasis on explanations based on neurotransmitters because emphasis on such explanations have been made largely by "educational" efforts funded by Boehringer-Ingelheim while it was attempting to get the FDA to approve a drug affecting neurotransmitters for treatment for HSDD. Low sexual desire can also be a side effect of various medications. In the case of acquired/situational HSDD, possible causes include intimacy difficulty, relationship problems, sexual addiction, and chronic illness of the man’s partner. The evidence for these is somewhat in question. Some claimed causes of low sexual desire are based on empirical evidence. However, some are based merely on clinical observation. In many cases, the cause of HSDD is simply unknown.

There are some factors that are believed to be possible causes of HSDD in women. As with men, various medical problems, psychiatric problems (such as mood disorders), or increased amounts of prolactin can cause HSDD. Other hormones are believed to be involved as well. Additionally, factors such as relationship problems or stress are believed to be possible causes of reduced sexual desire in women. According to one recent study examining the affective responses and attentional capture of sexual stimuli in women with and without HSDD, women with HSDD do not appear to have a negative association to sexual stimuli, but rather a weaker positive association than women without HSDD

Research has shown that paraphilias are rarely observed in women. However, there have been some studies on females with paraphilias. Sexual masochism has been found to be the most commonly observed paraphilia in women, with approximately 1 in 20 cases of sexual masochism being female.

Many acknowledge the scarcity of research on female paraphilias. The majority of paraphilia studies are conducted on people who have been convicted of sex crimes. Since the number of male convicted sex offenders far exceeds the number of female convicted sex offenders, research on paraphilic behavior in women is consequently lacking. Some researchers argue that an underrepresentation exists concerning pedophilia in females. Due to the low number of women in studies on pedophilia, most studies are based from "exclusively male samples". This likely underrepresentation may also be attributable to a "societal tendency to dismiss the negative impact of sexual relationships between young boys and adult women". Michele Elliott has done extensive research on child sexual abuse committed by females, publishing the book "Female Sexual Abuse of Children: The Last Taboo" in an attempt to challenge the gender-biased discourse surrounding sex crimes. John Hunsley states that physiological limitations in the study of female sexuality must also be acknowledged when considering research on paraphilias. He states that while a man's sexual arousal can be directly measured from his erection (see penile plethysmograph), a woman's sexual arousal cannot be measured as clearly (see vaginal photoplethysmograph), and therefore research concerning female sexuality is rarely as conclusive as research on men.

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 that may affect sexual desire or response. Over exposure to pornography-style media is also thought to lead to poor body image, self-consciousness and lowered self-esteem. 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.

GID exists when a person suffers discontent due to gender identity, causing them emotional distress. Researchers disagree about the nature of distress and impairment in people with GID. Some authors have suggested that people with GID suffer because they are stigmatized and victimized; and that, if society had less strict gender divisions, transsexual people would suffer less.

A twin study (based on seven people in a 314 sample) suggested that GID may be 62% heritable, indicating the possibility of a genetic influence or prenatal development as its origin, in these cases.

Sexual maturation disorder is a disorder of anxiety or depression related to an uncertainty about one's gender identity or sexual orientation. The World Health Organization (WHO) lists sexual maturation disorder in the ICD-10, under "Psychological and behavioural disorders associated with sexual development and orientation".

Sexual orientation, by itself, is not a disorder and is not classified under this heading. It differs from ego-dystonic sexual orientation where the sexual orientation or gender identity is repressed or denied.

Symptoms of GD in children may include any of the following: disgust at their own genitalia, social isolation from their peers, anxiety, loneliness and depression. According to the American Psychological Association, transgender children are more likely to experience harassment and violence in school, foster care, residential treatment centers, homeless centers and juvenile justice programs than other children.

Adults with GD are at increased risk for stress, isolation, anxiety, depression, poor self-esteem and suicide. Studies indicate that transgender people have an extremely high rate of suicide attempts; one study of 6,450 transgender people in the United States found 41% had attempted suicide, compared to a national average of 1.6%. It was also found that suicide attempts were less common among transgender people who said their family ties had remained strong after they came out, but even transgender people at comparatively low risk were still much more likely to have attempted suicide than the general population. Transgender people are also at heightened risk for certain mental disorders such as eating disorders.

Hypoactive sexual desire disorder (HSDD) or inhibited sexual desire (ISD) is considered a sexual dysfunction and is characterized as a lack or absence of sexual fantasies and desire for sexual activity, as judged by a clinician. For this to be regarded as a disorder, it must cause marked distress or interpersonal difficulties and not be better accounted for by another mental disorder, a drug (legal or illegal), some other medical condition, or asexuality. A person with ISD will not start, or respond to their partner's desire for, sexual activity.

There are various subtypes. HSDD can be general (general lack of sexual desire) or situational (still has sexual desire, but lacks sexual desire for current partner), and it can be acquired (HSDD started after a period of normal sexual functioning) or lifelong (the person has always had no/low sexual desire.)

HSDD has garnered much criticism, primarily by asexual activists. They point out that HSDD puts asexuality in the same position homosexuality was from 1974-1987. The DSM at that time recognised 'ego-dystonic homosexuality' as a disorder, defined as sexual interest in the same sex that caused significant distress. The DSM itself officially recognized this as unnecessarily pathologizing homosexuality and removed it as a disorder in 1987.

Fetishism usually becomes evident during puberty, and may develop prior to that. No cause for fetishism has been conclusively established.

Some explanations invoke classical conditioning. In several experiments, men have been conditioned to show arousal to stimuli like boots, geometric shapes or penny jars by pairing these cues with conventional erotica. According to John Bancroft, conditioning alone cannot explain fetishism, because it does not result in fetishism for most people. He suggests that conditioning combines with some other factor, such as an abnormality in the sexual learning process.

Theories of sexual imprinting propose that humans learn to recognize sexually desirable features and activities during childhood. Fetishism could result when a child is imprinted with an overly narrow or "incorrect" concept of a sex object. Imprinting seems to occur during the child's earliest experiences with arousal and desire, and is based on "an egocentric evaluation of salient reward- or pleasure-related characteristics that differ from one individual to another."

Neurological differences may play a role in some cases. Vilayanur S. Ramachandran observed that the region processing sensory input from the feet lies immediately next to the region processing genital stimulation, and suggested an accidental link between these regions could explain the prevalence of foot fetishism. In one unusual case, an anterior temporal lobectomy relieved an epileptic man's fetish for safety pins.

Various explanations have been put forth for the rarity of female fetishists. Most fetishes are visual in nature, and males are thought to be more sexually sensitive to visual stimuli. Roy Baumeister suggests that male sexuality is unchangeable, except for a brief period in childhood during which fetishism could become established, while female sexuality is fluid throughout life.

The prevalence of fetishism is not known with certainty. The majority of fetishists are male. In a 2011 study, 30% of men reported fetishistic fantasies, and 24.5% had engaged in fetishistic acts. Of those reporting fantasies, 45% said the fetish was intensely sexually arousing. In a 2014 study, 26.3% of women and 27.8% of men acknowledged any fantasies about "having sex with a fetish or non-sexual object". A content analysis of the sample's favorite fantasies found that 14% of the male fantasies involved fetishism (including feet, nonsexual objects, and specific clothing), and 4.7% focused on a specific body part other than feet. None of the women's favorite fantasies had fetishistic themes. Another study found that 28% of men and 11% of women reported fetishistic arousal (including feet, fabrics, and objects "like shoes, gloves, or plush toys"). 18% of men in a 1980 study reported fetishistic fantasies.

Fetishism to the extent that it becomes a disorder appears to be rare, with less than 1% of general psychiatric patients presenting fetishism as their primary problem. It is also uncommon in forensic populations.

The prevalence of pedophilia in the general population is not known, but is estimated to be lower than 5% among adult men. Less is known about the prevalence of pedophilia in women, but there are case reports of women with strong sexual fantasies and urges towards children. Most sexual offenders against children are male. Females may account for 0.4% to 4% of convicted sexual offenders, and one study estimates a 10 to 1 ratio of male-to-female child molesters. The true number of female child molesters may be underrepresented by available estimates, for reasons including a "societal tendency to dismiss the negative impact of sexual relationships between young boys and adult women, as well as women's greater access to very young children who cannot report their abuse", among other explanations.

The term "pedophile" is commonly used by the public to describe all child sexual abuse offenders. This usage is considered problematic by researchers, because many child molesters do not have a strong sexual interest in prepubescent children, and are consequently not pedophiles. There are motives for child sexual abuse that are unrelated to pedophilia, such as stress, marital problems, the unavailability of an adult partner, general anti-social tendencies, high sex drive, or alcohol use. As child sexual abuse is not automatically an indicator that its perpetrator is a pedophile, offenders can be separated into two types: pedophilic and non-pedophilic (or preferential and situational). Estimates for the rate of pedophilia in detected child molesters generally range between 25% and 50%. A 2006 study found that 35% of its sample of child molesters were pedophilic. Pedophilia appears to be less common in incest offenders, especially fathers and step-fathers. According to a U.S. study on 2429 adult male sex offenders who were categorized as "pedophiles", only 7% identified themselves as exclusive; indicating that many or most child sexual abusers may fall into the non-exclusive category.

Some pedophiles do not molest children. Little is known about this population because most studies of pedophilia use criminal or clinical samples, which may not be representative of pedophiles in general. Researcher Michael Seto suggests that pedophiles who commit child sexual abuse do so because of other anti-social traits in addition to their sexual attraction. He states that pedophiles who are "reflective, sensitive to the feelings of others, averse to risk, abstain from alcohol or drug use, and endorse attitudes and beliefs supportive of norms and the laws" may be unlikely to abuse children. A 2015 study indicates that pedophiles who molested children are neurologically distinct from non-offending pedophiles. The pedophilic molesters had neurological deficits suggestive of disruptions in inhibitory regions of the brain, while non-offending pedophiles had no such deficits.

According to Abel, Mittleman, and Becker (1985) and Ward "et al." (1995), there are generally large distinctions between the characteristics of pedophilic and non-pedophilic molesters. They state that non-pedophilic offenders tend to offend at times of stress; have a later onset of offending; and have fewer, often familial, victims, while pedophilic offenders often start offending at an early age; often have a larger number of victims who are frequently extrafamilial; are more inwardly driven to offend; and have values or beliefs that strongly support an offense lifestyle. One study found that pedophilic molesters had a median of 1.3 victims for those with girl victims and 4.4 for those with boy victims. Child molesters, pedophilic or not, employ a variety of methods to gain sexual access to children. Some groom their victims into compliance with attention and gifts, while others use threats, alcohol or drugs, or physical force.

The female sexual response system is complex and even today, not fully understood. The most prevalent of female sexual dysfunctions that have been linked to menopause include lack of desire and libido; these are predominantly associated with hormonal physiology. Specifically, it is the decline in serum estrogens that causes these changes in sexual functioning. Androgen depletion may also play a role, but currently this is less clear. The hormonal changes that take place during the menopausal transition have been suggested to affect women's sexual response through several mechanisms, some more conclusive than others.

Ego-dystonic sexual orientation is an ego-dystonic mental disorder characterized by having a sexual orientation or an attraction that is at odds with one's idealized self-image, causing anxiety and a desire to change one's orientation or become more comfortable with one's sexual orientation. It describes not innate sexual orientation itself, but a conflict between the sexual orientation one wishes to have and the sexual orientation one actually possesses.

Gender identity is a concept, specifically psychological, that refers to one's sense of being a male or female in regards to sexual orientation. Individuals who are diagnosed with gender identity disorder are classified as being dissatisfied with their anatomically determined gender.

Whether or not aging directly affects women's sexual functioning during menopause is another area of controversy. However, many studies, including Hayes and Dennerstein's critical review, have demonstrated that aging has a powerful impact on sexual function and dysfunction in women, specifically in the areas of desire, sexual interest, and frequency of orgasm. In addition, Dennerstien and colleagues found that the primary predictor of sexual response throughout menopause is prior sexual functioning. This means that it is important to understand how the physiological changes in men and women can affect their sexual desire. Despite the seemingly negative impact that menopause can have on sexuality and sexual functioning, sexual confidence and well-being can improve with age and menopausal status. Furthermore, the impact that a relationship status can have on quality of life is often underestimated.

Testosterone, along with its metabolite dihydrotestosterone, is extremely important to normal sexual functioning in men and women. Dihydrotestosterone is the most prevalent androgen in both men and women. Testosterone levels in women at age 60 are, on average, about half of what they were before the women were 40. Although this decline is gradual for most women, those who’ve undergone bilateral oophorectomy experience a sudden drop in testosterone levels; this is because the ovaries produce 40% of the body's circulating testosterone.

Sexual desire has been related to three separate components: drive, beliefs and values, and motivation. Particularly in postmenopausal women, drive fades and is no longer the initial step in a woman's sexual response (if it ever was).

Psychosexual disorders can vary greatly in severity and treatability. Medical professionals and licensed therapists are necessary in diagnosis and treatment plans. Treatment can vary from therapy to prescription medication. Sex therapy, behavioral therapy, and group therapy may be helpful to those suffering distress from sexual dysfunction. More serious sexual perversions may be treated with androgen blockers or selective serotonin reuptake inhibitors (SSRIs) to help restore hormonal and neurochemical balances.

Although what causes pedophilia is not yet known, researchers began reporting a series of findings linking pedophilia with brain structure and function, beginning in 2002. Testing individuals from a variety of referral sources inside and outside the criminal justice system as well as controls, these studies found associations between pedophilia and lower IQs, poorer scores on memory tests, greater rates of non-right-handedness, greater rates of school grade failure over and above the IQ differences, lesser physical height, greater probability of having suffered childhood head injuries resulting in unconsciousness, and several differences in MRI-detected brain structures. They report that their findings suggest that there are one or more neurological characteristics present at birth that cause or increase the likelihood of being pedophilic. Some studies have found that pedophiles are less cognitively impaired than non-pedophilic child molesters. A 2011 study reported that pedophilic child molesters had deficits in response inhibition, but no deficits in memory or cognitive flexibility. Evidence of familial transmittability "suggests, but does not prove that genetic factors are responsible" for the development of pedophilia. A 2015 study indicated that pedophilic offenders have a normal IQ.

Another study, using structural MRI, indicated that male pedophiles have a lower volume of white matter than a control group. Functional magnetic resonance imaging (fMRI) has indicated that child molesters diagnosed with pedophilia have reduced activation of the hypothalamus as compared with non-pedophilic persons when viewing sexually arousing pictures of adults. A 2008 functional neuroimaging study notes that central processing of sexual stimuli in heterosexual "paedophile forensic inpatients" may be altered by a disturbance in the prefrontal networks, which "may be associated with stimulus-controlled behaviours, such as sexual compulsive behaviours". The findings may also suggest "a dysfunction at the cognitive stage of sexual arousal processing".

Blanchard, Cantor, and Robichaud (2006) reviewed the research that attempted to identify hormonal aspects of pedophiles. They concluded that there is some evidence that pedophilic men have less testosterone than controls, but that the research is of poor quality and that it is difficult to draw any firm conclusion from it.

While not causes of pedophilia themselves, childhood abuse by adults or comorbid psychiatric illnesses—such as personality disorders and substance abuse—are risk factors for acting on pedophilic urges. Blanchard, Cantor, and Robichaud addressed comorbid psychiatric illnesses that, "The theoretical implications are not so clear. Do particular genes or noxious factors in the prenatal environment predispose a male to develop both affective disorders and pedophilia, or do the frustration, danger, and isolation engendered by unacceptable sexual desires—or their occasional furtive satisfaction—lead to anxiety and despair?" They indicated that, because they previously found mothers of pedophiles to be more likely to have undergone psychiatric treatment, the genetic possibility is more likely.

A study analyzing the sexual fantasies of 200 heterosexual men by using the Wilson Sex Fantasy Questionnaire exam determined that males with a pronounced degree of paraphilic interest (including pedophilia) had a greater number of older brothers, a high 2D:4D digit ratio (which would indicate low prenatal androgen exposure), and an elevated probability of being left-handed, suggesting that disturbed hemispheric brain lateralization may play a role in deviant attractions.

Sexual sadism disorder is the condition of experiencing sexual arousal in response to the extreme pain, suffering or humiliation of others. Several other terms have been used to describe the condition, and the condition may overlap with other conditions that involve inflicting pain. It is distinct from situations in which consenting individuals use mild or simulated pain or humiliation for sexual excitement. The words "sadism" and "" are derived from Marquis de Sade.

In the United States, following a series of landmark cases in the Supreme Court of the United States, persons diagnosed with paraphilias, particularly pedophilia ("Kansas v. Hendricks", 1997) and exhibitionism ("Kansas v. Crane", 2002), with a history of anti-social behavior and related criminal history, can be held indefinitely in civil confinement under various state legislation generically known as sexually violent predator laws and the federal Adam Walsh Act ("United States v. Comstock", 2010).

As the disorder progresses in life, it can increase in severity, and cause other behaviors or actions in late adolescence and adulthood. “A strong and persistent cross-gender identification in adolescents and adults [can cause a] disturbance manifested by symptoms such as a stated desire to be the other sex, frequent passing as the other sex, desire to live or be treated as the other sex, or the conviction that he or she has the typical feelings and reactions of the other sex” (APA, 2000). This can cause severe conflict for the individual living in a society which endorses and enforces adherence to strict gender roles. In a more persistent disassociation with one’s own body or gender, someone can go to more extreme lengths to feel as though they are fulfilled or satisfied with themselves. This can lead these individuals to engage in behavior that displaces their emotions. These individuals may also seek to undergo sex reassignment surgery. “Persistent discomfort with his or her sex or sense of inappropriateness in the gender role of that sex in adolescents and adults [can cause a] disturbance manifested by symptoms such as preoccupation with getting rid of primary and secondary sex characteristics (e.g., request for hormones, surgery, or other procedures to physically alter sexual characteristics to simulate the other sex) or belief that he or she was born the wrong sex” (APA, 2000).

The prevalence of frotteurism is unknown. The DSM estimates that 10%–14% of men seen in clinical settings for paraphilias or hypersexuality have frotteuristic disorder, indicating that the population prevalence is lower. However, frotteuristic acts, as opposed to frotteuristic disorder, may occur in up to 30% of men in the general population. The majority of frotteurs are male and the majority of victims are female, although female on male, female on female, and male on male frotteurs exist. This activity is often done in circumstances where the victim cannot easily respond, in a public place such as a crowded train or concert.

Usually, such nonconsensual sexual contact is viewed as a criminal offense: a form of sexual assault albeit often classified as a misdemeanor with minor legal penalties. Conviction may result in a sentence or psychiatric treatment.

There are many ways a person may go about receiving therapy for ego-dystonic sexual orientation associated with homosexuality. There is no known therapy for other types of ego-dystonic sexual orientations. Therapy can be aimed at changing sexual orientation, sexual behaviour, or helping a client become more comfortable with their sexual orientation and behaviours. Human rights groups have accused some countries of performing these treatments on egosyntonic homosexuals. One survey suggested that viewing the same-sex activities as compulsive facilitated commitment to a mixed-orientation marriage and to monogamy. Treatment may include sexual orientation change efforts or treatment to alleviate the stress. In addition, some people seek non-professional methods, such as religious counselling or attendance in an ex-gay group.

Erotophobia is a term coined by a number of researchers in the late 1970s and early 1980s to describe one pole on a continuum of attitudes and beliefs about sexuality. The model of the continuum is a basic polarized line, with erotophobia (fear of sex or negative attitudes about sex) at one end and erotophilia (positive feelings or attitudes about sex) at the other end.

The word erotophobia is derived from the name of Eros, the Greek god of erotic love, and Phobos, Greek (φόβος) for "fear".

The person experiences sneezing as a result of sexual thoughts, arousal, intercourse, or orgasm. Sneezing occurs independent of external nasal stimuli or allergens, and may occur at any point during a sexual experience. Both men and women are affected by the phenomenon.

Frotteurism is a paraphilic interest in rubbing, usually one's pelvic area or erect penis, against a non-consenting person for sexual pleasure. It may involve touching any part of the body, including the genital area. A person who practices frotteuristic acts is known as a "frotteur". Toucherism is sexual arousal based on grabbing or rubbing one's hands against an unexpecting (and non-consenting) person. It usually involves touching breasts, buttocks or genital areas, often while quickly walking across the victim's path. Some psychologists consider toucherism a manifestation of frotteurism, while others distinguish the two. In clinical medicine, treatment of frotteuristic disorder involves cognitive behavior therapy coupled with the administration of a SSRI.