Erectile dysfunction (ED) is the inability of a man to achieve or maintain an erection sufficient for his or his partner's sexual needs. Most men experience this at some point in their lives, usually by age 40. Incidence of the disorder generally increases with age. Erectile dysfunction affects about 5% of men in their 40's and 15-25% of men by the age of 65.
50% of men over the age of 40 may experience transient Erectile dysfunction and inadequate erection. Physical or psychological stimulation (arousal) results in significant blood flow to the penis.
