【资料】ED的动画（附解说原文）

Erectile Dysfunction - ED

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. ED affects about 5% of men in their 40s and 15-25% of men by the age of 65. 50% of men over the age of 40 may experience transient ED and inadequate erection.

Physical or psychological stimulation (arousal) results in significant blood flow to the penis. The arteries in the penis supply blood to erectile tissue, which become engorged and expands as a result of increased blood flow and pressure. This constricts the fibrous elastic sheathes that cinch to prevent blood from leaving the penis during erection.

Causes of Erectile Dysfunction

Reduced blood flow to the penis and nerve damage are the most common physical causes. Underlying conditions associated with erectile dysfunction include the following:

Vascular disease
Diabetes
Drugs
Hormone disorders
Neurologic conditions
Pelvic trauma, surgery, radiation therapy
Peyronie's disease
Venous leak
Psychological condition