Erectile dysfunction (ED) is the inability to get or keep an erection firm enough for sexual intercourse. ED can be a total inability to achieve an erection, an inconsistent ability to do so, or a tendency to sustain only brief erections.
ED is sometimes called impotence, but that word is being used less often so that it will not be confused with other, nonmedical meanings of the term.
The National Institutes of Health estimates that ED affects as many as 30 million men in the United States. Incidence increases with age: About 4 percent of men in their 50s and nearly 17 percent of men in their 60s experience a total inability to achieve an erection. The incidence jumps to 47 percent for men older than 75.2 But ED is not an inevitable part of aging. ED is treatable at any age.