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.

For both diagnoses, symptoms must persist for at least six months, cause clinically significant distress, and not be better explained by another condition. Simply having lower desire than one's partner is not sufficient for a diagnosis. Self-identification of a lifelong lack of sexual desire as asexuality precludes diagnosis.

The American Psychiatric Association permits a diagnosis of "gender dysphoria" if the criteria in the DSM-5 are met. The DSM-5 moved this diagnosis out of the sexual disorders category and into a category of its own. The DSM-5 states that at least two of the criteria for gender dysphoria must be experienced for at least six months' duration in adolescents or adults for diagnosis. The diagnosis was renamed from "Gender Identity Disorder" to "Gender Dysphoria", after criticisms that the former term was stigmatizing. Subtyping by sexual orientation was deleted. The diagnosis for children was separated from that for adults, as "gender dysphoria in children". The creation of a specific diagnosis for children reflects the lesser ability of children to have insight into what they are experiencing, or ability to express it in the event that they have insight.

The International Classification of Diseases (ICD-10) list three diagnostic criteria for "transsexualism" (F64.0): Uncertainty about gender identity which causes anxiety or stress is diagnosed as sexual maturation disorder, according to the ICD-10.

The question of whether to counsel young children to be happy with their assigned sex, or to encourage them to continue to exhibit behaviors that do not match their assigned sex—or to explore a transsexual transition—is controversial. Some clinicians report that a significant proportion of young children diagnosed with gender dysphoria later do not exhibit any dysphoria.

Professionals who treat gender identity disorder in children have begun to refer and prescribe hormones, known as a puberty blocker, to delay the onset of puberty until a child is believed to be old enough to make an informed decision on whether hormonal gender reassignment leading to surgical gender reassignment will be in that person's best interest.

HSDD, like many sexual dysfunctions, is something that people are treated for in the context of a relationship. Theoretically, one could be diagnosed with, and treated for, HSDD without being in a relationship. However, relationship status is the most predictive factor accounting for distress in women with low desire and distress is required for a diagnosis of HSDD. Therefore, it is common for both partners to be involved in therapy. Typically, the therapist tries to find a psychological or biological cause of the HSDD. If the HSDD is organically caused, the clinician may try to deal with that. If the clinician believes it is rooted in a psychological problem, they may recommend therapy for that. If not, treatment generally focuses more on relationship and communication issues, improved communication (verbal and nonverbal), working on non-sexual intimacy, or education about sexuality may all be possible parts of treatment. Sometimes problems occur because people have unrealistic perceptions about what normal sexuality is and are concerned that they do not compare well to that, and this is one reason why education can be important. If the clinician thinks that part of the problem is a result of stress, techniques may be recommended to more effectively deal with that. Also, it can be important to understand why the low level of sexual desire is a problem for the relationship because the two partners may associate different meaning with sex but not know it.

In the case of men, the therapy may depend on the subtype of HSDD. Increasing the level of sexual desire of a man with lifelong/generalized HSDD is unlikely. Instead the focus may be on helping the couple to adapt. In the case of acquired/generalized, it is likely that there is some biological reason for it and the clinician may attempt to deal with that. In the case of acquired/situational, some form of psychotherapy may be used, possibly with the man alone and possibly together with his partner.

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.

When the WHO removed the diagnosis of homosexuality as a mental disorder in ICD-10, it included the diagnosis of "ego-dystonic sexual orientation" under "Psychological and behavioural disorders associated with sexual development and orientation". The WHO's ICD-10 diagnoses ego-dystonic sexual orientation thus:

The gender identity or sexual preference (heterosexual, homosexual, bisexual, or prepubertal) is not in doubt, but the individual wishes it were different because of associated psychological and behavioural disorders, and may seek treatment in order to change it. ()

The WHO notes that for codes under F66: "Sexual orientation by itself is not to be regarded as a disorder."

Patients are sometimes still diagnosed as having this problem. This is often a result of unfavorable and intolerant attitudes of the society or a conflict between sexual urges and religious belief systems.

The DSM-IV-TR criteria was criticized simultaneously for being over-inclusive, as well as under-inclusive. Though most researchers distinguish between child molesters and pedophiles, Studer and Aylwin argue that the DSM criteria are over-inclusive because all acts of child molestation warrant the diagnosis. A child molester satisfies criteria A because of the behavior involving sexual activity with prepubescent children and criteria B because the individual has acted on those urges. Furthermore, they argue that it also is under-inclusive in the case of individuals who do not act upon it and are not distressed by it. The latter point has also been made by several other researchers who have remarked that a so-called "contented pedophile"—an individual who fantasizes about having sex with a child and masturbates to these fantasies, but does not commit child sexual abuse, and who does not feel subjectively distressed afterward—does not meet the DSM-IV-TR criteria for pedophilia, because this person does not meet Criterion B. A large-scale survey about usage of different classification systems showed that the DSM classification is only rarely used. As an explanation, it was suggested that the under-inclusiveness, as well as a lack of validity, reliability and clarity might have led to the rejection of the DSM classification.

Ray Blanchard, an American-Canadian sexologist known for his research studies on pedophilia, addressed (in his literature review for the DSM-5) the aforementioned objections to the DSM-IV-TR, and proposed a general solution applicable to all paraphilias. This meant namely a distinction between "paraphilia" and "paraphilic disorder". The latter term is proposed to identify the diagnosable mental disorder which meets Criterion A and B, whereas an individual who does not meet Criterion B can be ascertained but "not" diagnosed as having a paraphilia. Blanchard and a number of his colleagues also proposed that hebephilia become a diagnosable mental disorder under the DSM-5 to resolve the physical development overlap between pedophilia and hebephilia by combining the categories under "pedophilic disorder", but with specifiers on which age range (or both) is the primary interest. The proposal for hebephilia was rejected by the American Psychiatric Association, but the distinction between "paraphilia" and "paraphilic disorder" was implemented.

The American Psychiatric Association stated that "[i]n the case of pedophilic disorder, the notable detail is what wasn't revised in the new manual. Although proposals were discussed throughout the DSM-5 development process, diagnostic criteria ultimately remained the same as in DSM-IV TR" and that "[o]nly the disorder name will be changed from pedophilia to pedophilic disorder to maintain consistency with the chapter’s other listings." If hebephilia had been accepted as a DSM-5 diagnosable disorder, it would have been similar to the ICD-10 definition of pedophilia that already includes early pubescents, and would have raised the minimum age required for a person to be able to be diagnosed with pedophilia from 16 years to 18 years (with the individual needing to be at least 5 years older than the minor).

O'Donohue, however, suggests that the diagnostic criteria for pedophilia be simplified to the attraction to children alone if ascertained by self-report, laboratory findings, or past behavior. He states that any sexual attraction to children is pathological and that distress is irrelevant, noting "this sexual attraction has the potential to cause significant harm to others and is also not in the best interests of the individual." Also arguing for behavioral criteria in defining pedophilia, Howard E. Barbaree and Michael C. Seto disagreed with the American Psychiatric Association's approach in 1997 and instead recommended the use of actions as the sole criterion for the diagnosis of pedophilia, as a means of taxonomic simplification.

The FDA has approved one medication for the treatment of disorders of female libido, flibanserin.

The ICD-10 defines fetishism as a reliance on non-living objects for sexual arousal and satisfaction. It is only considered a disorder when fetishistic activities are the foremost source of sexual satisfaction, and become so compelling or unacceptable as to cause distress or interfere with normal sexual intercourse. The ICD's research guidelines require that the preference persists for at least six months, and is markedly distressing or acted on.

Under the DSM-5, fetishism is sexual arousal from nonliving objects or specific nongenital body parts, excluding clothes used for cross-dressing (as that falls under transvestic disorder) and sex toys that are designed for genital stimulation. In order to be diagnosed as "fetishistic disorder", the arousal must persist for at least six months and cause significant psychosocial distress or impairment in important areas of their life. In the DSM-IV, sexual interest in body parts was distinguished from fetishism under the name partialism (diagnosed as Paraphilia NOS), but it was merged with fetishistic disorder for the DSM-5.

The ReviseF65 project has campaigned for the ICD diagnosis to be abolished completely to avoid stigmatizing fetishists. Sexologist Odd Reiersøl argues that distress associated with fetishism is often caused by shame, and that being subject to diagnosis only exacerbates that. He suggests that, in cases where the individual fails to control harmful behavior, they instead be diagnosed with a personality or impulse control disorder.

In the DSM-5 all paraphilia disorders can be diagnosed by two main criteria that are referred to criteria A and criteria B respectively. The A and B criteria include a duration in which the behavior must be present for (typically 6 months) and specific details of actions or thoughts that are correlated specifically with the respective disorder being diagnosed.

The "Diagnostic and Statistical Manual of Mental Disorders" 5th edition (DSM-5) has a significantly larger diagnostic features section for pedophilia than the previous DSM version, the DSM-IV-TR, and states, "The diagnostic criteria for pedophilic disorder are intended to apply both to individuals who freely disclose this paraphilia and to individuals who deny any sexual attraction to prepubertal children (generally age 13 years or younger), despite substantial objective evidence to the contrary." Like the DSM-IV-TR, the manual outlines specific criteria for use in the diagnosis of this disorder. These include the presence of sexually arousing fantasies, behaviors or urges that involve some kind of sexual activity with a prepubescent child (with the diagnostic criteria for the disorder extending the cut-off point for prepubescence to age 13) for six months or more, or that the subject has acted on these urges or suffers from distress as a result of having these feelings. The criteria also indicate that the subject should be 16 or older and that the child or children they fantasize about are at least five years younger than them, though ongoing sexual relationships between a 12- to 13-year-old and a late adolescent are advised to be excluded. A diagnosis is further specified by the sex of the children the person is attracted to, if the impulses or acts are limited to incest, and if the attraction is "exclusive" or "nonexclusive".

The ICD-10 defines pedophilia as "a sexual preference for children, boys or girls or both, usually of prepubertal or early pubertal age". Like the DSM, this system's criteria require that the person be at least 16 years of age or older before being diagnosed as a pedophile. The person must also have a persistent or predominant sexual preference for prepubescent children at least five years younger than them.

Several terms have been used to distinguish "true pedophiles" from non-pedophilic and non-exclusive offenders, or to distinguish among types of offenders on a continuum according to strength and exclusivity of pedophilic interest, and motivation for the offense (see child sexual offender types). Exclusive pedophiles are sometimes referred to as "true pedophiles." They are sexually attracted to prepubescent children, and only prepubescent children. Showing no erotic interest in adults, they can only become sexually aroused while fantasizing about or being in the presence of prepubescent children, or both. Non-exclusive offenders—or "non-exclusive pedophiles"—may at times be referred to as "non-pedophilic" offenders, but the two terms are not always synonymous. Non-exclusive offenders are sexually attracted to both children and adults, and can be sexually aroused by both, though a sexual preference for one over the other in this case may also exist. If the attraction is a sexual preference for prepubescent children, such offenders are considered pedophiles in the same vein as exclusive offenders.

Neither the DSM nor the ICD-10 diagnostic criteria require actual sexual activity with a prepubescent youth. The diagnosis can therefore be made based on the presence of fantasies or sexual urges even if they have never been acted upon. On the other hand, a person who acts upon these urges yet experiences no distress about their fantasies or urges can also qualify for the diagnosis. "Acting" on sexual urges is not limited to overt sex acts for purposes of this diagnosis, and can sometimes include indecent exposure, voyeuristic or frotteuristic behaviors, or masturbating to child pornography. Often, these behaviors need to be considered in-context with an element of clinical judgment before a diagnosis is made. Likewise, when the patient is in late adolescence, the age difference is not specified in hard numbers and instead requires careful consideration of the situation.

Ego-dystonic sexual orientation () includes people who acknowledge that they have a sexual preference for prepubertal children, but wish to change it due to the associated psychological or behavioral problems (or both).

Most psychologists believe that paraphilic sexual interests cannot be altered. Instead, the goal of therapy is normally to reduce the person's discomfort with their paraphilia and limit any criminal behavior. Both psychotherapeutic and pharmacological methods are available to these ends.

Cognitive behavioral therapy, at times, can help people with paraphilias develop strategies to avoid acting on their interests. Patients are taught to identify and cope with factors that make acting on their interests more likely, such as stress. It is currently the only form of psychotherapy for paraphilias supported by evidence.

Antiandrogens are used in more severe cases. Similar to physical castration, they work by reducing androgen levels, and have thus been described as chemical castration. The antiandrogen cyproterone acetate has been shown to substantially reduce sexual fantasies and offending behaviors. Medroxyprogesterone acetate and gonadotropin-releasing hormone agonists (such as leuprolide acetate) have also been used to lower sex drive. Due to the side effects, the World Federation of Societies of Biological Psychiatry recommends that hormonal treatments only be used when there is a serious risk of sexual violence, or when other methods have failed. Surgical castration has largely been abandoned because these pharmacological alternatives are similarly effective and less invasive.

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.

According to the World Health Organization, fetishistic fantasies are common and should only be treated as a disorder when they impair normal functioning or cause distress. Goals of treatment can include elimination of criminal activity, reduction in reliance on the fetish for sexual satisfaction, improving relationship skills, or attempting to remove deviant arousal altogether. The evidence for treatment efficacy is limited and largely based on case studies, and no research on treatment for female fetishists exists.

Cognitive behavioral therapy is one popular approach. Cognitive behavioral therapists teach clients to identify and avoid antecedents to fetishistic behavior, and substitute non-fetishistic fantasies for ones involving the fetish. Aversion therapy can reduce fetishistic arousal in the short term, but is unlikely to have any permanent effect.

Antiandrogens and selective serotonin reuptake inhibitors (SSRIs) may be prescribed to lower sex drive. Cyproterone acetate is the most commonly used antiandrogen, except in the United States, where it may not be available. A large body of literature has shown that it reduces general sexual fantasies. Side effects may include osteoporosis, liver dysfunction, and feminization. Case studies have found that the antiandrogen medroxyprogesterone acetate is successful in reducing sexual interest, but can have side effects including osteoporosis, diabetes, deep vein thrombosis, feminization, and weight gain. Some hospitals use leuprolide acetate and goserelin acetate to reduce libido, and while there is presently little evidence for their efficacy, they have fewer side effects than other antiandrogens. A number of studies support the use of SSRIs, which may be preferable over antiandrogens because of their relatively benign side effects. None of these drugs cure sexual fetishism, but they can make it easier to manage.

Relationship counselers may attempt to reduce dependence on the fetish and improve partner communication using techniques like sensate focusing. Partners may agree to incorporate the fetish into their activities in a controlled, time-limited manner, or set aside only certain days to practice the fetishism. If the fetishist cannot sustain an erection without the fetish object, the therapist might recommend orgasmic reconditioning or covert sensitization to increase arousal to normal stimuli (although the evidence base for these techniques is weak).

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

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

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.

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 6 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".

A thorough sexual history and assessment of general health and other sexual problems (if any) are very important. Assessing performance anxiety, guilt, stress and worry are integral to the optimal management of sexual dysfunction. Many of the sexual dysfunctions that are defined are based on the human sexual response cycle, proposed by William H. Masters and Virginia E. Johnson, and then modified by Helen Singer Kaplan.

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.

Several decades ago the medical community believed the majority of sexual dysfunction cases were related to psychological issues. Although this may be true for a portion of men, the vast majority of cases have now been identified as having a physical cause or correlation. If the sexual dysfunction is deemed to have a psychological component or cause, psychotherapy can help. Situational anxiety arises from an earlier bad incident or lack of experience. This anxiety often leads to development of fear towards sexual activity and avoidance. In return evading leads to a cycle of increased anxiety and desensitization of the penis. In some cases, erectile dysfunction may be due to marital disharmony. Marriage counseling sessions are recommended in this situation.

Lifestyle changes such as discontinuing smoking, drug or alcohol abuse can also help in some types of erectile dysfunction.

Several oral medications like Viagra, Cialis and Levitra have become available to help people with erectile dysfunction and have become first line therapy. These medications provide an easy, safe, and effective treatment solution for approximately 60% of men. In the rest, the medications may not work because of wrong diagnosis or chronic history.

Another type of medication that is effective in roughly 85% of men is called intracavernous pharmacotherapy and involves injecting a vasodilator drug directly into the penis in order to stimulate an erection. This method has an increased risk of priapism if used in conjunction with other treatments, and localized pain.

When conservative therapies fail, are an unsatisfactory treatment option, or are contraindicated for use, the insertion of a penile prosthesis, or penile implant, may be selected by the patient. Technological advances have made the insertion of a penile prosthesis a safe option for the treatment of erectile dysfunction which provides the highest patient and partner satisfaction rates of all available ED treatment options.

Pelvic floor physical therapy has been shown to be a valid treatment for men with sexual problems and pelvic pain.

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).

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 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.

With paraphilic coercive disorder, the individual employs enough force to subdue a victim, but with sexual sadism disorder, the individual often continues to inflict harm regardless of the compliance of the victim, which sometimes escalates not only to the death of the victim, but also to the mutilation of the body. What is experienced by the sadist as sexual does not always appear obviously sexual to non-sadists: Sadistic rapes do not necessarily include penile penetration of the victim. In a survey of offenses, 77% of cases included sexual bondage, 73% included anal rape, 60% included blunt force trauma, 57% included vaginal rape, and 40% included penetration of the victim by a foreign object. Moreover, in 40% of cases, the offender kept a personal item of the victim as a souvenir.

On personality testing, sadistic rapists apprehended by law enforcement have shown elevated traits of impulsivity, hypersexuality, callousness, and psychopathy.

Although there appears to be a continuum of severity from mild ("hyperdominance" or "BDSM") to moderate ("paraphilic coercive disorder") to severe ('sexual sadism disorder), it is not clear if they are genuinely related or only appear related superficially.

Very little is known about how sexual sadism disorder develops. Most of the people diagnosed with sexual sadism disorder come to the attention of authorities by committing sexually motivated crimes. Surveys have also been conducted including people who are interested in only mild and consensual forms of sexual pain/humiliation (BDSM).

Most of the people with full-blown sexual sadism disorder are male, whereas the sex ratio of people interested in BDSM is closer to 2:1 male-to-female.

People with sexual sadism disorder" are at an elevated likelihood of having other paraphilic sexual interests.

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.