Research
In modern times, clinical study of sexual problems is usually dated back no earlier than 1970 when Masters and Johnsons Human Sexual Inadequacy was published. It was the result of over a decade of work at the Reproductive Biology Research Foundation in St. Louis, involving 790 cases. The work grew from Masters and Johnsons earlier Human Sexual Response (1966). Prior to Masters and Johnson, the clinical approach to sexual problems was largely derived from Sigmund Freud. It was held to be psychopathology and approached with a certain pessimism regarding the chance of help or improvement. Sexual problems were merely symptoms of a deeper malaise, and the diagnostic approach was from the psychopathological viewpoint. There was little distinction between difficulties in function and variations nor between perversion and problems. Despite work by psychotherapists such as Balint sexual difficulties were crudely split into frigidity or impotence, terms which acquired negative connotations in popular culture. Human Sexual Inadequacy moved thinking from psychopathology to learning; psychopathological problems would only be considered if a problem did not respond to educative treatment. Treatment was directed at couples, whereas before partners would be seen individually. Masters and Johnson believed that sex was a joint act, and that sexual communication was the key issue to sexual problems, not the specifics of an individual problem. They also proposed co-therapy, with a pair of therapists to match the clients, arguing that a lone male therapist could not fully comprehend female difficulties.
Although this decline is gradual for most women, those who have undergone bilateral oophorectomy experience a sudden drop in testosterone levels, as the ovaries produce 40% of the bodys 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 womans sexual response. Diagnosis
List of disorders
DSM
The fourth edition of the Diagnostic and Statistical Manual of Mental Disorders lists the following sexual dysfunctions:

Hypoactive sexual desire disorder (see also asexuality, which is not classified as a disorder)
Sexual aversion disorder (avoidance of or lack of desire for sexual intercourse)
Female sexual arousal disorder (failure of normal lubricating arousal response)
Male erectile disorder
Female orgasmic disorder (see anorgasmia)
Male orgasmic disorder (see anorgasmia)
Premature ejaculation
Dyspareunia
VaginismusAdditional DSM sexual disorders that are not sexual dysfunctions include:

Paraphilias
PTSD due to genital mutilation or childhood sexual abuse

Other sexual problems
Sexual dissatisfaction (non-specific)
Lack of sexual desire
Anorgasmia
Impotence
Sexually transmitted diseases
Delay or absence of ejaculation, despite adequate stimulation
Inability to control timing of ejaculation
Inability to relax vaginal muscles enough to allow intercourse
Inadequate vaginal lubrication preceding and during intercourse
Burning pain on the vulva or in the vagina with contact to those areas
Unhappiness or confusion related to sexual orientation
Transsexual and transgender people may have sexual problems before or after surgery. Persistent sexual arousal syndrome
Sexual addiction
Hypersexuality
All forms of female genital cutting
Post-orgasmic diseases, such as Dhat syndrome, PCT, POIS, and sexual headacheS. Treatment
Males
Several decades ago, the medical community believed most sexual dysfunction cases were related to psychological issues.