Impotence is inability of the male to have satisfactory sexual intercourse and varies in form from the inability to gain an erection to weak erections, premature ejaculation, or loss of normal sensation with ejaculation. It may be caused by subnormal functioning of the testes, by arteriosclerosis (hardening of the arteries), by diabetes, by psychological factors, or by a disease of the nervous system. Certain medications prescribed for the treatment of such diseases as peptic ulcer, hypertension, or psychiatric illness may adversely affect sexual ability. Therapy includes drug therapy (PDE-5 inhibitors such as Viagra), administration of hormones, or psychotherapy.
Priapism
Priapism is prolonged penile erection that is painful and unassociated with sexual stimulation. The blood in the spaces of the corpora cavernosa becomes sludgelike and may remain for hours or even days. About 25 percent of the cases are associated with leukemia, sickle cell anemia, metastatic carcinoma (cancerous development at a distance from the primary site), or diseases of the nervous system, but in the majority of cases the causation is not clear. There have been many forms of treatment, but drug therapy is effective in most cases. Regardless of treatment, impotence is common after an episode of priapism and even more common after repeated episodes of priapism.
Nicholas A. Romas John Kingsley LattimerSexually transmitted diseases
Sexually transmitted diseases (STDs), also called venereal diseases, are usually contracted during sexual intercourse with an infected partner. The principal disorders commonly transmitted in this manner include AIDS, syphilis, gonorrhea, chlamydia, and genital herpes.