Erectile dysfunction - definition and patterns

Erectile dysfunction (ED) is the inability of a male to achieve or to maintain an erection of adequate quality and duration to permit satisfactory sexual performance and sexual gratification. It can occur in a man whose libido (sex drive) is intact (and therefore unfulfilled), or it can be associated with decreased or absent sex drive. ED is not a disease per se, but rather the clinical manifestation of one or more organic and/or psychogenic conditions. ED is not necessarily an all or none problem; rather, it is usually a matter of degree, ranging from minor to complete. It cuts across race, nationality, and socioeconomic factors; occurs at all ages; and varies in severity and duration from man to man. Almost all married men experience occasional episodes of ED.

Patterns of ED differ among men. Some men lose their erections when they get anxious; some can achieve erections only during foreplay; others may gain an erection only to lose it at the moment of penetration or during intercourse. Some men may have erections through masturbation, or only in deviant situations (e.g., with pornography or during unusual sexual encounters), but fail to achieve or maintain erections under normal circumstances or with their primary sexual partner - such a man is anatomically potent, but psychologically he has ED.

Diagnosis, treatments and therapies

Any organic or psychological disorder that affects the brain, nervous system, vascular system, endocrine system, or genitourinary system - or, even more specifically, affects any part of the penis - can lead to a man's inability to develop or maintain a firm erection for a period long enough for successful sexual intercourse.

All healthy men, regardless of age, develop spontaneous erections during sleep. Evaluating these erections helps differentiate, to a degree, psychological ED from physical ED. This assessment, however, cannot be the sole basis for diagnosis. Accurate diagnosis depends on review of the patient's medical, psychosocial, sexual, and familial histories; a proper physical examination; the results of some laboratory tests; and an open, frank discussion between the doctor and patient. The doctor needs to know when and how the sexual symptoms began as well as their character, nature, severity, and impact on the couple; document any previous illnesses or surgical procedures; and inquire about marital, familial, social, or professional factors that may contribute to the sexual dysfunction.

When ED is due to physical causes, it can be treated with oral drugs, vacuum devices, intracorporeal injections, intraurethral inserts, vascular surgery, or the insertion of a penile prosthesis. But it should be noted that in a substantial number of cases, behavioral changes such as smoking cessation, daily exercise, treating obesity, lowering serum cholesterol, curing alcohol and drug addiction, and substituting or changing medications by the treating specialist may restore the man's erectile ability without the need for any further therapy.

When ED is caused by psychological factors, treatment varies from behavioral and psychoanalytic therapy to sexual and marital therapy. Several psychological tactics to relieve performance anxiety; modify behavior; improve sexual communication between partners; acquire sexual skills; and eliminate taboos, misconceptions, and negative attitudes toward sex are employed. Full cooperation of the couple is required for successful treatment.

Prevalence and epidemiology

In the United States alone, ED affects about 15 to 30 million men. About 48% of the American male population over the age of 50 may suffer from ED, with the incidence increasing with age to reach about 75% in men 70 or older. It is estimated that in total, about 150 million men worldwide suffer from some degree of ED, and it is projected that this number will double by the year 2025, as the male population becomes increasingly older. These figures, however, doubtless underestimate the true global prevalence of ED.