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.

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.

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.

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.

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.

"Sex reassignment therapy" (SRT) is an umbrella term for all medical treatments related to sex reassignment of both transgender and intersex people.

Individuals make different choices regarding sex reassignment therapy, which may include female-to-male or male-to-female hormone replacement therapy (HRT) to modify secondary sex characteristics, sex reassignment surgery (such as orchiectomy) to alter primary sex characteristics, chest surgery such as top surgery or breast augmentation, or, in the case of trans women, a trachea shave, facial feminization surgery or permanent hair removal.

To obtain sex reassignment therapy, transsexual people are generally required to undergo a psychological evaluation and receive a diagnosis of gender identity disorder in accordance with the Standards of Care (SOC) as published by the World Professional Association for Transgender Health. This assessment is usually accompanied by counseling on issues of adjustment to the desired gender role, effects and risks of medical treatments, and sometimes also by psychological therapy. The SOC are intended as guidelines, not inflexible rules, and are intended to ensure that clients are properly informed and in sound psychological health, and to discourage people from transitioning based on unrealistic expectations.

In May 2013, the American Psychiatric Association published the DSM-5 in which the GIDC diagnosis was removed and replaced with gender dysphoria, for the first time in its own distinct chapter. Lev states that gender dysphoria places the focus on distress with one's body rather than conformity with societal gender norms, and that this change was accompanied by changes to sexist language and a reduced reliance on binary gender categories. Gender dysphoria reframes the diagnosis as a time-limited distress of the body which is potentially rectified with access to gender transition procedures, rather than a lifetime disorder of the identity.

Children with persistent GID are characterized by more extreme gender dysphoria in childhood than children with desisting gender dysphoria. Some (but not all) gender diverse / gender independent / gender fluid youth will want or need to transition, which may involve social transition (changing dress, name, pronoun), and, for older youth and adolescents, medical transition (hormonal and surgical intervention). Treatment may take the form of puberty blockers such as Lupron Depot or Leuprolide Acetate, or cross-sex hormones (i.e., administering estrogen to an assigned male at birth or testosterone to an assigned female at birth), or surgery (i.e., mastectomies, salphingo-oophorectomies/hysterectomy, the creation of a neophallus in female-to-male transsexuals, orchiectomies, breast augmentation, facial feminization surgery, the creation of a neovagina in male-to-female transsexuals), with the aim of bringing one’s physical body in line with their felt gender. The ability to transition (socially and medically) are sometimes needed in the treatment of gender dysphoria.

The Endocrine Society does not recommend endocrine treatment of prepubertal children because clinical experience suggests that GID can be reliably assessed only after the first signs of puberty. It recommends treating transsexual adolescents by suppressing puberty with puberty blockers until age 16 years old, after which cross-sex hormones may be given.

The University of Washington is leading the largest study of transgender youth ever conducted. The study, known as the Transgender Youth Project, looks at 300 transgender kids between the ages of 3 and 12. Researchers hope to follow the children for 20 years.

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.

Transsexualism appears in the International Statistical Classification of Diseases and Related Health Problems (ICD, currently in its tenth edition). The ICD-10 incorporates "transsexualism", "dual role transvestism," and "gender identity disorder of childhood" into its gender identity disorder category. It defines transsexualism as "[a] desire to live and be accepted as a member of the opposite sex, usually accompanied by a sense of discomfort with, or inappropriateness of, one's anatomic sex, and a wish to have surgery and hormonal treatment to make one's body as congruent as possible with one's preferred sex."

Historically, transsexualism has also been included in the American Psychiatric Association's "Diagnostic and Statistical Manual of Mental Disorders" (DSM). With the DSM-5, transsexualism was removed as a diagnosis, and a diagnosis of gender dysphoria was created in its place. This change was made to reflect the consensus view by members of the APA that transsexuality is not in and of itself a disorder and that transsexual people should not be stigmatized unnecessarily. By including a diagnosis for gender dysphoria, transsexual people are still able to access medical care through the process of transition.

Similarly, the World Professional Association for Transgender Health (WPATH), and many transsexual people, have recommended the removal of transsexualism from the mental health chapter of the upcoming ICD, ICD-11 (due to be released in 2018). They argue that at least some mental health professionals are being insensitive by labelling transsexualism as "a disease", rather than the inborn trait which those who have it believe it to be. Principle 18 of The Yogyakarta Principles, a document of international human rights law, opposes such diagnosis as mental illness as medical abuse.

The current diagnosis for transsexual people who present themselves for medical treatment is gender dysphoria (leaving out those who have sexual identity disorders without gender concerns). According to the "Standards of care" formulated by the World Professional Association for Transgender Health (WPATH), formerly the Harry Benjamin International Gender Dysphoria Association, this diagnostic label is often necessary to obtain sex reassignment therapy with health insurance coverage, and the designation of gender identity disorders as mental disorders is not a license for stigmatization or for the deprivation of gender patients' civil rights.

Males with late onset gender dysphoria "frequently" display transvestic fetishism.

Some male transvestic fetishists collect women's clothing, e.g. panties, nightgowns, babydolls, bridal gowns, slips, brassieres, and other types of nightwear, lingerie, stockings, pantyhose, shoes, and boots, items of a distinct feminine look and feel. They may dress in these feminine garments and take photographs of themselves while living out their fantasies.

According to DSM-IV, this fetishism was limited to heterosexual men; however, DSM-5 does not have this restriction, and opens it to women and men with this interest, regardless of their sexual orientation.

There are two key criteria before a psychiatric diagnosis of "transvestic fetishism" is made:

1. Individuals must be sexually aroused by the act of cross-dressing.

2. Individuals must experience significant distress or impairment – socially or occupationally – because of their behavior.

Transvestic fetishism is a psychiatric diagnosis applied to those who are thought to have an excessive sexual or erotic interest in cross-dressing; this interest is often expressed in autoerotic behavior. It differs from cross-dressing for entertainment or other purposes that do not involve sexual arousal, and is categorized as a paraphilia in the Diagnostic and Statistical Manual of the American Psychiatric Association. (Sexual arousal in response to donning sex-typical clothing is homeovestism.)

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).

Phallophobia in its narrower sense is a fear of the erect penis and in a broader sense an excessive aversion to masculinity.

Macrophilia is a fascination with or a sexual fantasy involving giants, more commonly expressed as giantesses (female giants). It is typically a male fantasy, with the male playing the "smaller" part—entering, being dominated, or being eaten by the larger woman. Others involve partners who naturally have a significant difference in size.

Transmisogyny (sometimes trans-misogyny) is the intersection of transphobia and misogyny. Transphobia is defined as "the irrational fear of, aversion to, or discrimination against transgender or transsexual people". Misogyny is defined as "a hatred of women". Therefore, transmisogyny includes negative attitudes, hate, and discrimination of transgender or transsexual individuals who fall on the feminine side of the gender spectrum, particularly transgender women. The term was coined by Julia Serano in her 2007 book "Whipping Girl" and used to describe the unique discrimination faced by trans women because of "the assumption that femaleness and femininity are inferior to, and exist primarily for the benefit of, maleness and masculinity", and the way that transphobia intensifies the misogyny faced by trans women (and vice versa). It is said many trans women experience an additional layer of misogyny in the form of fetishization; Serano talks about how society views trans women in certain ways that sexualize them, such as them transitioning for sexual reasons, or ways where they’re seen as sexually promiscuous.Transmisogyny is a central concept in transfeminism and is commonly referenced in intersectional feminist theory. That trans women's femaleness (rather than only their femininity) is a source of transmisogyny is denied by certain radical feminists, who claim that trans women are not female.

Although macrophilia literally translates to simply a "lover of large," in the context of a sexual fantasy, it is used to mean someone who is attracted to beings larger than themselves. Generally, the interest differs between people, and depends on gender and sexual orientation. They often enjoy feeling small and being abused, degraded, dominated, or eaten, and they may also view female giants as being powerful and dominating.

Commenting on why there are not as many female macrophiles, psychologist Helen Friedman theorized that because women in most societies already view men as dominant and powerful, there is no need for them to fantasize about it. Women that take on the roles of the giantess within this fetish often find the practice to be empowering and enjoy being worshipped.

The roots of macrophilia may lie in sexual arousal in childhood and early adolescence which is accidentally associated with giants, according to Dr. Mark Griffiths's speculation.

Sigmund Freud has footnoted the possibility that this fear may be derived from a lack of ingenuity allowing one to ornamentally distance the copulatory organs from the excretory organs. Such a condition can affect both men and women. For others, symptoms include what characterizes a panic attack. It does not necessarily have to be induced by an uncovered penis, but may also result from seeing the manbulging outline or curvature of the penis, perhaps through clothes consisting of thin fabric. In more extreme cases it has been likened to the fight or flight response ingrained within the human body wherein an individual ceases to be intimate with their male partner and is unable to visit mixed gender establishments where people are likely to wear more revealing clothing, such as a gym, beach, cinema or livingrooms with a switched on monitor. The fear can recur through any of the senses including accidental touch, sight, hearing the word penis or thinking about an erection. The phobia may have developed from a condition such as dyspareunia, a trauma (usually sexual) that occurred during childhood, but can also have a fortuitous origin. In literature covering human sexuality, it is used as an adjective only to negatively allude to penetrative sex acts. Men who have the phobia may try to avoid wearing jeans and other light fabrics, especially in public. Some analysts have purported that the condition may be inherited or may be a combination of genetic inheritance and life experiences. For men with the condition, one of the byproducts is difficulty consummating with a partner due to a sense of vulnerability. This vulnerability may have developed during childhood because they grew up being told by their parents that sex and its physiological functions were evil, sinful and dirty, but were subsequently unable to detach such shameful feelings nor reverse it upon reaching adulthood, even when romantic initiatives were subsequently approved of or encouraged by their parents.

There is no universal cure for genophobia. Some ways of coping with or treating anxiety issues is to see a psychiatrist, psychologist, or licensed counselor for therapy. Some people experiencing pain during sex may visit their doctor or gynecologist. Medicine may also be prescribed to treat the anxiety brought on by the phobia.

Transphobia is a range of negative attitudes, feelings or actions toward transgender or transsexual people, or toward transsexuality. Transphobia can be emotional disgust, fear, violence, anger or discomfort felt or expressed towards people who do not conform to society's gender expectations. It is often expressed alongside homophobic views and hence is often considered an aspect of homophobia. Transphobia is a type of prejudice and discrimination similar to racism and sexism, and transgender people of color are often subjected to all three forms of discrimination at once.

Child victims of transphobia experience harassment, school bullying, and violence in school, foster care, and social programs. Adult victims experience public ridicule, harassment including misgendering, taunts, threats of violence, robbery, and false arrest; many feel unsafe in public. A high percentage report being victims of sexual violence. Some are refused healthcare or suffer workplace discrimination, including being fired for being transgender, or feel under siege by conservative political or religious groups who oppose laws to protect them. There is even discrimination from some people within the movement for the rights of gender and sexual minorities.

Besides the increased risk of violence and other threats, the stress created by transphobia can cause negative emotional consequences which may lead to substance abuse, running away from home (in minors), and a higher rate of suicide.

In the Western world, there have been gradual changes towards the establishment of policies of non-discrimination and equal opportunity. The trend is also taking shape in developing nations. In addition, campaigns regarding the LGBT community are being spread around the world to improve acceptance; the "Stop the Stigma" campaign by the UN is one such development.

Obsessive love is a condition in which one person feels an overwhelming obsessive desire to possess and protect another person toward whom one feels a strong attraction, with an inability to accept failure or rejection. Although not categorized specifically under any specific mental diagnosis by the DSM-5, some people argue that obsessive love is considered to be a mental illness similar to attachment disorder, borderline personality disorder, and erotomania. Depending on the intensity of their attraction, obsessive lovers may feel entirely unable to restrain themselves from extreme behaviors such as acts of violence toward themselves or others. Obsessive love can have its roots in childhood trauma, and may begin at first sight; it may persist indefinitely, sometimes requiring psychotherapy.

Obsessive love occurs in both women and men, making it a gender neutral phenomenon.

Women's fear of crime refers to women's fear of being a victim of crime, independent of actual victimization. Although fear of crime is a concern for people of all genders, studies consistently find that women around the world tend to have much higher levels of fear of crime than men, despite the fact that in many places, and for most offenses, men's actual victimization rates are higher. Fear of crime is related to perceived risk of victimization, but is not the same; fear of crime may be generalized instead of referring to specific offenses, and perceived risk may also be considered a demographic factor that contributes to fear of crime. Women tend to have higher levels for both perceived risk and fear of crime.

In women's everyday lives, fear of crime can have negative effects, such as reducing their environmental mobility. Studies have shown that women tend to avoid certain behaviors, such as walking alone at night, because they are fearful of crime, and would feel more comfortable with these behaviors if they felt safer.

Dual-role transvestism is the formal diagnosis used by psychologists and physicians to describe people who wear clothes of the opposite sex to experience being the opposite sex temporarily, but don't have a sexual motive or want gender reassignment surgery. The International Classification of Diseases (ICD-10) list three diagnostic criteria for "Dual-role transvestism" (F64.1):

A person who is diagnosed with Dual-role transvestism should not receive a diagnosis of transvestic fetishism(F65.1),

Transmisogyny is generally understood to be caused by the social belief that men are superior to women. In "Whipping Girl", Julia Serano writes that the existence of trans women is seen as a threat to a "male-centered gender hierarchy, where it is assumed that men are better than women and that masculinity is superior to femininity". Gender theorist Judith Butler echoes this assumption, stating that the murder of transgender women is "an act of power, a way of re-asserting domination... killing establishes the killer as sovereign in the moment that he kills".

Trans women are also viewed as threatening the heterosexuality of cisgender men. In media, "deceivers" such as Dil, a transgender woman from the 1992 film "The Crying Game", have been observed to invoke outrage and male homophobia in an audience when their "true" maleness is unveiled.