Updated: May 5
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.
Okay. Got that? So, what are some of the factors that lead to decreased bloodflow?
The one unavoidable factor is aging. There’s only one way to avoid aging and we all want to put that off as long as possible. As we age, the arteries tend to develop thicker, less elastic walls, so they expand less with sexual stimulation thus they cannot deliver as much blood to the penis.
There are other factors, either alone or in combination, which may lead to ED.
Arteriosclerotic vascular disease (hardening of the arteries) causes plaque buildup in the walls of the arteries. The arteries become stiff and unable to dilate. High blood pressure also leads to thickening of the arterial walls due to their being constantly exposed to the force of the blood flowing through them. Some of the medications used to treat high blood pressure can interfere with the chemical pathways that cause erections. So high blood pressure is a double whammy for your erection.
Diabetes and obesity also lead to poor bloodflow due to the release of free radicals and other “toxic” molecules. These molecules damage the cells lining the walls of the vessels causing plaques to form as well as reducing the cells ability to release nitric oxide, a vasodilator.
As mentioned, certain blood pressure medications, as well as antidepressants and antianxiety medications can interfere in the biochemical pathways that are involved in the erectile process.
Trauma to the penis or the surrounding tissue can also factor in ED. A poorly fitting or narrow bicycle seat may compress the soft tissue at the base of the penis, causing numbness that is usually temporary but could become permanent if the compression occurs over a long period of time.
Personal habits such as smoking, excessive alcohol use, or poor dietary choices will also factor in the erectile equation.
These and other issues are the physical and medical factors that may lead to ED. Psychological factors are another separate but important issue in the discussion and understanding of ED.
The staff and physician of Renewal Medical Centers of North Texas are available to answer any questions you may have regarding the diagnosing and treatment of Erectile Dysfunction.