Erectile dysfunction (ED) is the inability to attain or sustain an erection satisfactory for sexual intercourse.
Every man occasionally has a problem achieving an erection, and such occurrences are considered normal. Erectile dysfunction occurs when a man is
Never able to achieve an erection
Achieves erection briefly but not long enough for intercourse
Achieves effective erection inconsistently
ED is called primary if the man has never been able to attain or sustain an erection.
ED is called secondary if it is acquired later in life by a man who was previously able to attain erections.
Secondary ED is much more common than primary ED.
In the United States, about 50% of men aged 40 to 70 are affected somewhat, and the percentage increases with aging. However, ED is not considered a normal part of aging and can be successfully treated at any age.