Sexual dysfunction is difficulty experienced by an individual or a couple during any stage of a normal sexual activity, including physical pleasure, desire, preference, arousal or orgasm. According to the DSM-5, sexual dysfunction requires a person to feel extreme distress and interpersonal strain for a minimum of six months (excluding substance or medication-induced sexual dysfunction).Sexual dysfunctions can have a profound impact on an individual's perceived quality of sexual life. The term sexual disorder may not only refer to physical sexual dysfunction, but to paraphilias as well; this is sometimes termed disorder of sexual preference. 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 dysfunction disorders may be classified into four categories: sexual desire disorders, arousal disorders, orgasm disorders and pain disorders. Sexual dysfunction among men and women are specifically studied in the fields of andrology and gynaecology.