ASK DR.K: Why Is This Happening to Me?

Updated: Mar 11

Dear Dr. K, “What causes ED?”

To understand the cause of Erectile Dysfunction or ED, you first need to understand how you get an erection.

Look at your penis (wait until you’re somewhere private). You’ll see that your penis is made up of three cylindrical structures, two on top and one on the bottom. The tube on the bottom contains the urethra through which urine and semen pass. The 2 tubes on the top are called the cavernous bodies (don’t worry there won’t be a quiz later.) Each of these cylinders is filled with a spongy, vascular network that engorges with blood, causing the penis to enlarge and become hard. These tubes are encased by a tough sheath of elastic tissue (tunic albuginea) that helps maintain the rigidity of the erect penis.

With sexual stimulation, the arteries supplying blood to the penis dilate and more blood is pumped into the cavernous bodies causing them to swell and become rigid. (Think of a water balloon. The more water, the firmer the balloon.) Anything that impedes the bloodflow into the penis will lead to ED.