Erectile dysfunction, sometimes called impotence, affects 10% of the entire American male population.  However, less than 5% with erectile dysfunction (ED) seek treatment. What is erectile dysfunction?  And, what causes ED?

Penis erection
Blood flow in and out of the penis controls an erection.  During sexual arousal, a blood flow increases to two spongy, structures (corpus cavemosum) that lie parallel to the urethra, which carries urine and semen.  These structures enlarge with blood, and allow the penis to stiffen and become erect.  A decrease in sexual arousal-for example, after ejaculation-allows blood to more easily flow out of the penis, which allows the penis to change size and shape and become flaccid.

What is erectile dysfunction?
Erectile dysfunction occurs when a man cannot have an erection for enough time to have sex, or other sexual activity.  ED manifests as either:

• an ability to achieve erection, but inability to control ejaculation
• an inability to maintain erections
• an occasional ability to achieve erection
• total inability to achieve erection