The World Health Organization (WHO) lists ego-dystonic sexual orientation in the ICD-10, as a disorder of sexual development and orientation. The WHO diagnosis covers when gender identity or sexual orientation is clear, yet a patient has another behavioural or psychological disorder which makes that patient want to change it. The diagnostic manual notes that a sexual orientation is not a disorder in itself. The World Health Organization (WHO) notes that any particular sexual orientation (heterosexuality, homosexuality, or bisexuality) is not a mental disorder by and of itself.

Similarly, the American Psychological Association has officially opposed the category of ego-dystonic homosexuality since 1987. In 2007, a task force of the American Psychological Association undertook a thorough review of the existing research on the efficacy of reparative therapy for. Their report noted that there was very little methodologically sound research on sexual orientation change efforts (SOCEs) and that the "results of scientifically valid research indicate that it is unlikely that individuals will be able to reduce same-sex attractions or increase other-sex sexual attractions through SOCE." In addition, the task force found that "there are no methodologically sound studies of recent SOCE that would enable the task force to make a definitive statement about whether or not recent SOCE is safe or harmful and for whom." The diagnostic category of "ego-dystonic homosexuality" was removed from the American Psychiatric Association's DSM in 1987 (with the publication of the DSM-III-R). Sexual disorders are still present in the DSM under the category of "sexual disorder not otherwise specified". One of the disorders under this category is "persistent and marked distress about one’s sexual orientation”, which can be considered similar to what WHO describes as ego-dystonic sexual orientation.

The Medical Council of India uses the WHO classification of ego-dystonic sexual orientation. The "Chinese Classification and Diagnostic Criteria of Mental Disorders" includes ego-dystonic homosexuality.

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.

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.

Psychosexual disorder is a term which may simply refer to a sexual problem that is psychological, rather than physiological in origin. "Psychosexual disorder" was a term used in . The term of psychosexual disorder (Turkish: "Psikoseksüel bozukluk") used by the TAF for homosexuality as a reason to ban the LGBT people from military service.

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.

Paraphilia (previously known as sexual perversion and sexual deviation) is the experience of intense sexual arousal to atypical objects, situations, fantasies, behaviors, or individuals. Such attraction may be labeled sexual fetishism. No consensus has been found for any precise border between unusual sexual interests and paraphilic ones. There is debate over which, if any, of the paraphilias should be listed in diagnostic manuals, such as the "Diagnostic and Statistical Manual of Mental Disorders" (DSM) or the International Classification of Diseases (ICD).

The number and taxonomy of paraphilia is under debate; one source lists as many as 549 types of paraphilia. The DSM-5 has specific listings for eight paraphilic disorders. Several sub-classifications of the paraphilias have been proposed, and some argue that a fully dimensional, spectrum or complaint-oriented approach would better reflect the evidence.

Pedophilia or paedophilia is a psychiatric disorder in which an adult or older adolescent experiences a primary or exclusive sexual attraction to prepubescent children. Although girls typically begin the process of puberty at age 10 or 11, and boys at age 11 or 12, criteria for pedophilia extend the cut-off point for prepubescence to age 13. A person who is diagnosed with pedophilia must be at least 16 years old, and at least five years older than the prepubescent child, for the attraction to be diagnosed as pedophilia.

Pedophilia is termed pedophilic disorder in the "Diagnostic and Statistical Manual of Mental Disorders" (DSM-5), and the manual defines it as a paraphilia involving intense and recurrent sexual urges towards and fantasies about prepubescent children that have either been acted upon or which cause the person with the attraction distress or interpersonal difficulty. The International Classification of Diseases (ICD-10) defines it as a sexual preference for children of prepubertal or early pubertal age.

In popular usage, the word "pedophilia" is often applied to any sexual interest in children or the act of child sexual abuse. This use conflates the sexual attraction to prepubescent children with the act of child sexual abuse, and fails to distinguish between attraction to prepubescent and pubescent or post-pubescent minors. Researchers recommend that these imprecise uses be avoided because although people who commit child sexual abuse are sometimes pedophiles, child sexual abuse offenders are not pedophiles unless they have a primary or exclusive sexual interest in prepubescent children, and some pedophiles do not molest children.

Pedophilia was first formally recognized and named in the late 19th century. A significant amount of research in the area has taken place since the 1980s. Although mostly documented in men, there are also women who exhibit the disorder, and researchers assume available estimates underrepresent the true number of female pedophiles. No cure for pedophilia has been developed, but there are therapies that can reduce the incidence of a person committing child sexual abuse. The exact causes of pedophilia have not been conclusively established. Some studies of pedophilia in child sex offenders have correlated it with various neurological abnormalities and psychological pathologies. In the United States, following "Kansas v. Hendricks", sex offenders who are diagnosed with certain mental disorders, particularly pedophilia, can be subject to indefinite civil commitment.

In a review of 48 cases of clinical fetishism, fetishes included clothing (58.3%), rubber and rubber items (22.9%), footwear (14.6%), body parts (14.6%), leather (10.4%), and soft materials or fabrics (6.3%). A 2007 study counted members of Internet discussion groups with the word "fetish" in their name. Of the groups about body parts or features, 47% belonged to groups about feet (foot fetishism), 9% about body fluids, 9% about body size, 7% about hair (hair fetish), and 5% about muscles (muscle worship). Less popular groups focused on navels (navel fetishism), legs, body hair, mouth, and nails, among other things. Of the groups about clothing, 33% belonged to groups about clothes worn on the legs or buttocks (such as stockings or skirts), 32% about footwear (shoe fetishism), 12% about underwear (underwear fetishism), and 9% about whole-body wear such as jackets. Less popular object groups focused on headwear, stethoscopes, wristwear, and diapers (diaper fetishism).

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.

The professional handbook of the American Psychiatric Association (APA), the "Diagnostic and Statistical Manual of Mental Disorders", fifth edition, lists the following diagnostic criteria for "frotteuristic disorder".

- Over a period of at least 6 months, recurrent and intense sexual arousal from touching or rubbing against a nonconsenting person, as manifested by fantasies, urges, or behaviors.

- The individual has acted on these sexual urges with a nonconsenting person, or the sexual urges or fantasies cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.

If the individual has not acted on their interest and experiences no distress or impairment, they are considered to have a frotteuristic sexual interest, but not frotteuristic disorder. Some sexologists distinguish between frotteurism (as pelvic rubbing) and toucherism (as groping with hands), but the DSM does not. Sexologist Kurt Freund described frotteurism and toucherism as courtship disorders that occur at the tactile stage of human courtship.

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.

The word "pedophilia" comes from the ("paîs, paidós"), meaning "child", and φιλία ("philía"), "friendly love" or "friendship". "Pedophilia" is used for individuals with a primary or exclusive sexual interest in prepubescent children aged 13 or younger.

"Infantophilia" is a sub-type of pedophilia; it is used to refer to a sexual preference for children under the age of 5 (especially infants and toddlers). This is sometimes referred to as "nepiophilia" (from the ("népios") meaning "infant" or "child," which in turn derives from "ne-" and "epos" meaning "not speaking"), though this term is rarely used in academic sources. "Hebephilia" is defined as individuals with a primary or exclusive sexual interest in 11- to 14-year-old pubescents. The DSM-5 does not list hebephilia among the diagnoses; while evidence suggests that hebephilia is separate from pedophilia, the ICD-10 includes early pubertal age (an aspect of hebephilia) in its pedophilia definition, covering the physical development overlap between the two philias. In addition to "hebephilia", some clinicians have proposed other categories that are somewhat or completely distinguished from pedophilia; these include "pedohebephilia" (a combination of pedophilia and hebephilia) and "ephebophilia" (though ephebophilia is not considered pathological).

Coprophilia (from Greek "κόπρος, kópros—excrement" and "φιλία, philía—liking, fondness"), also called scatophilia or scat (Greek: "σκατά, skatá-feces"), is the paraphilia involving sexual arousal and pleasure from feces. In the "Diagnostic and Statistical Manual of Mental Disorders" (DSM), published by the American Psychiatric Association, it is classified under 302.89 – Paraphilia NOS (Not Otherwise Specified) and has no diagnostic criteria other than a general statement about paraphilias that says "the diagnosis is made if the behavior, sexual urges, or fantasies cause clinically significant distress or impairment in social, occupational, or other important areas of functioning". Furthermore, the DSM-IV-TR notes, "Fantasies, behaviors, or objects are paraphilic only when they lead to clinically significant distress or impairment (e.g. are obligatory, result in sexual dysfunction, require participation of nonconsenting individuals, lead to legal complications, interfere with social relationships)".

Although there may be no connection between coprophilia and sadomasochism (SM), the limited data on the former comes from studies of the latter. A study of 164 males in Finland from two SM clubs found that 18.2% had engaged in coprophilia; 3% as a sadist, 6.1% as a masochist, and 9.1% as both. 18% of heterosexuals and 17% of homosexuals in the study pool had tried coprophilia, showing no statistically significant difference between heterosexuals and homosexuals. In a separate article analyzing 12 men who engaged in bestiality, an additional analysis of an 11-man subgroup revealed that 6 had engaged in coprophilic behavior, compared with only 1 in the matched control group consisting of 12 SM-oriented males who did not engage in bestiality.

HSDD was listed under the Sexual and Gender Identity Disorders of the DSM-IV. In the DSM-5, it was split into male hypoactive sexual desire disorder and female sexual interest/arousal disorder. It was first included in the DSM-III under the name inhibited sexual desire disorder, but the name was changed in the DSM-III-R. Other terms used to describe the phenomenon include sexual aversion and sexual apathy. More informal or colloquial terms are "frigidity" and "frigidness".

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.

The DSM-5 adds a distinction between "paraphilias" and "paraphilic disorders", stating that paraphilias do not require or justify psychiatric treatment in themselves, and defining "paraphilic disorder" as "a paraphilia that is currently causing distress or impairment to the individual or a paraphilia whose satisfaction has entailed personal harm, or risk of harm, to others".

The DSM-5 Paraphilias Subworkgroup reached a "consensus that paraphilias are not "ipso facto" psychiatric disorders", and proposed "that the DSM-V make a distinction between "paraphilias" and paraphilic "disorders". [...] One would "ascertain" a paraphilia (according to the nature of the urges, fantasies, or behaviors) but "diagnose" a paraphilic disorder (on the basis of distress and impairment). In this conception, having a paraphilia would be a necessary but not a sufficient condition for having a paraphilic disorder." The 'Rationale' page of any paraphilia in the electronic DSM-5 draft continues: "This approach leaves intact the distinction between normative and non-normative sexual behavior, which could be important to researchers, but without automatically labeling non-normative sexual behavior as psychopathological. It also eliminates certain logical absurdities in the DSM-IV-TR. In that version, for example, a man cannot be classified as a transvestite—however much he cross-dresses and however sexually exciting that is to him—unless he is unhappy about this activity or impaired by it. This change in viewpoint would be reflected in the diagnostic criteria sets by the addition of the word "Disorder" to all the paraphilias. Thus, Sexual Sadism would become Sexual Sadism Disorder; Sexual Masochism would become Sexual Masochism Disorder, and so on."

Bioethics professor Alice Dreger interpreted these changes as "a subtle way of saying sexual kinks are basically okay – so okay, the sub-work group doesn’t actually bother to define paraphilia. But a paraphilic disorder is defined: that’s when an atypical sexual interest causes distress or impairment to the individual or harm to others." Interviewed by Dreger, Ray Blanchard, the Chair of the Paraphilias Sub-Work Group, explained: "We tried to go as far as we could in depathologizing mild and harmless paraphilias, while recognizing that severe paraphilias that distress or impair people or cause them to do harm to others are validly regarded as disorders."

Charles Allen Moser pointed out that this change is not really substantive as DSM-IV already acknowledged a difference between paraphilias and non-pathological but unusual sexual interests, a distinction that is virtually identical to what is being proposed for DSM-5, and it is a distinction that, in practice, has often been ignored. Linguist Andrew Clinton Hinderliter argued that "Including some sexual interests—but not others—in the DSM creates a fundamental asymmetry and communicates a negative value judgment against the sexual interests included," and leaves the paraphilias in a situation similar to ego-dystonic homosexuality, which was removed from the DSM because it was realized not to be a mental disorder.

The DSM-5 acknowledges that many dozens of paraphilias exist, but only has specific listings for eight that are forensically important and relatively common. These are voyeuristic disorder, exhibitionistic disorder, frotteuristic disorder, sexual masochism disorder, sexual sadism disorder, pedophilic disorder, fetishistic disorder, and transvestic disorder. Other paraphilias can be diagnosed under the Other Specified Paraphilic Disorder or Unspecified Paraphilic Disorder listings, if accompanied by distress or impairment.

Zoophilia is a paraphilia involving a sexual fixation on non-human animals. Bestiality is cross-species sexual activity between human and non-human animals. The terms are often used interchangeably, but some researchers make a distinction between the attraction (zoophilia) and the act (bestiality).

Although sex with animals is not outlawed in some countries, in most countries, bestiality is illegal under animal abuse laws or laws dealing with buggery or crimes against nature.

Biphobia is aversion toward bisexuality and toward bisexual people as a social group or as individuals. It can take the form of denial that bisexuality is a genuine sexual orientation, or of negative stereotypes about people who are bisexual (such as the beliefs that they are promiscuous or dishonest). People of any sexual orientation can experience or perpetuate biphobia, and it is a source of social discrimination against bisexual people.

Biastophilia (from Greek "biastes", "rape" + "-philia") and its Latin language-derived counterpart raptophilia (from Latin "rapere", "to seize"), also paraphilic rape, is a paraphilia in which sexual arousal is dependent on, or is responsive to, the act of assaulting an unconsenting person, especially a stranger. Some dictionaries consider the terms synonymous, while others distinguish raptophilia as the paraphilia in which sexual arousal is responsive to actually raping the victim.

The source of the arousal in these paraphilias is the victim's terrified resistance to the assault, and in this respect it is considered to be a form of sexual sadism. Biastophilia is accepted as potentially lethal, other such paraphilias including, but not being limited to asphyxiophilia, autassassinophilia, hybristophilia, and chremastistophilia.

Under the name paraphilic coercive disorder, this diagnosis was proposed for inclusion in DSM-5. This diagnosis, under the name "paraphilic rapism", was proposed and rejected in the DSM-III-R. It has been criticized because of the impossibility of reliably distinguishing between paraphilic rapists and non-paraphilic rapists, and because this diagnosis, under the term "Paraphilia NOS" (not otherwise specified), non-consent had been used in Sexually Violent Person/Predator commitment.

Czech sexology standardly use a concept of pathologic sexual aggressivity instead. This term is strongly distinguished from sadism. This disorder is understood as a coordination anomaly of the sexual motivation system (SMS), a "courtship disorder" according to Kurt Freund or displacement paraphilia by John Money, or a missing segment of SMS.

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.

The Cleveland steamer is a colloquial term for a form of coprophilia, where someone defecates on their partner's chest.

The term received news attention through its use in a U.S. Congress staff hoax email and being addressed by the United States Federal Communications Commission.

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.

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

Although female sexual dysfunction is currently a contested diagnostic, it has become more common in recent years to use testosterone-based drugs off-label to treat FSAD. While drug companies are technically not allowed to market these drugs for off-label uses, sharing the information with doctors at CME conferences has proved to be an effective way to navigate around the FDA approval process.

Sexual dysfunction disorders may be classified into four categories: sexual desire disorders, arousal disorders, orgasm disorders and pain disorders.

Sexual obsessions are obsessions with sexual activity. In the context of obsessive-compulsive disorder (OCD), these are extremely common, and can become extremely debilitating, making the person ashamed of the symptoms and reluctant to seek help. As preoccupation with sexual matters, however, does not only occur as a symptom of OCD, they may be enjoyable in other contexts (i.e. sexual fantasy).