Erectile dysfunction (ED) is the inability of a man to achieve or maintain an erection sufficient for his sexual needs or the needs of his partner. Most men experience this at some point in their lives, usually by age 40, and are not psychologically affected by it.
Some men, however, experience chronic, complete erectile dysfunction (impotence), and others, partial or brief erections. Frequent erectile dysfunction can cause emotional and relationship problems, and often leads to diminished self-esteem. Erectile dysfunction has many causes, most of which are treatable, and is not an inevitable consequence of aging.
The term "erectile dysfunction" can mean the inability to achieve erection, an inconsistent ability to do so, or the ability to achieve only brief erections. These various definitions make estimating the incidence of erectile dysfunction difficult.
According to the National Institutes of Health, an estimated 30 million men in the United States experience chronic erectile dysfunction and incidence of the disorder increases with age. Chronic ED affects about 4% of men in their 50s, nearly 17% of men in their 60s, and about 47% of men over the age of 75. Transient ED and inadequate erection affect as many as 50% of men between the ages of 40 and 70.
Diseases (e.g., diabetes, kidney disease, alcoholism, atherosclerosis) account for as many as 70% of chronic ED cases and psychological factors (e.g., stress, anxiety, depression) may account for 10–20% of cases. Between 35 and 50% of men with diabetes experience ED.