Sexual Medicine or Sexology is the scientific study of human sexual behaviours, interests and function and deals with dysfunction in males and females like erectile dysfunction, premature ejaculation, arousal disorder etc. Most of the sexual functions depend on the proper functioning of sex hormones like androgens, oestrogen, oxytocin, prolactin and neurotransmitters like dopamine and serotonin. Sexual medicine is part of Endocrinology.

The common sexual dysfunctions in the male are hypoactive sexual desire disorder. erectile dysfunction, premature ejaculation and delayed ejaculation. The common sexual dysfunctions in the female are arousal/desire disorder, anorgansmic disorder and genito-pelvic pain/penetration disorder (vaginismus).

In addition, sexual medicine also include disorders of puberty (precocious puberty, delayed puberty), childhood masturbation, disorders of sexual differentiation, menopause (genitourinary syndrome of menopause), hypogonadism, gender identity disorder, gender orientation disorder etc. Premarital counselling and sex therapy by cognitive behavioural therapy (CBT) and sensate focus are used to counsel and treat patients with sexual dysfunctions.

Male hypoactive sexual desire disorder refers to the absence of sexual thoughts, fantasies or desire for sexual activity. Erectile dysfunction refers to difficulty in obtaining an erection or maintaining an erection during sexual activity or marked decrease in rigidity of penis. Low desire and erectile dysfunction can be due to many reasons like vascular, neurologic, endocrine causes (diabetes, thyroid dysfunction and hypogonadism), drugs and psychogenic. Presence of one problem can cause other sexual dysfunction. Desire disorder can be treated after understanding personal, relationship, couple dynamics and underlying hormonal and medical disorders. Erectile dysfunction can be treated by drugs, couple therapy, etc

Premature ejaculation is defined as persistent pattern of early ejaculation within one minute following vaginal penetration and before the individual wishes it. Premature ejaculation can be lifelong, acquired or situational. Premature ejaculation can coexist with erectile dysfunction. Delayed ejaculation refers to marked delay ore absence of ejaculation. Treatment of premature ejaculation includes behavioural treatment and drugs with a good response.

Female sexual interest arousal disorder refers to reduced interest, initiation, fantasy, thoughts, pleasure and sensations. Female orgasmic disorder refers to reduced intensity of orgasmic sensation. Genito-pelvic pain/penetration disorders include difficulty and pain on insertion with anxiety and spasmodic tightening of pelvic floor muscles. Female sexual dysfunction is treated by drugs, couple therapy and sensate focus.

Male hypogonadism can cause low desire, erectile dysfunction and body weakness can be due to hypogonadism. Hypogonadism is diagnosed by testing blood in the morning fasting sample of total testosterone. If total testosterone is below the 300ng/dl, we need additional testing like LH, Prolactin, etc. Additional tests like MRI pituitary or genetic testing may be required. Hypogonadism is easily treated by tablets, cream or injections.

Gender orientation disorder refers to the sexual orientation that is the sex of the person to whom one is equally attracted. Gender identity disorder commonly called transgender refers to a person whose gender does not match with the gender assigned to that person at birth and includes trans-man and trans-woman and are treated with sex reassignment surgery and hormones.