DEAR DOCTOR K:
My doctor says my erectile dysfunction is most likely caused by vascular disease. Can you explain the connection?
Erectile dysfunction (ED) — trouble attaining and sustaining an erection — is quite common in men over age 40. Why, you might ask, would nature (evolution) not preserve something so important to the continued existence of the human race? The average life expectancy throughout most of human history has been less than 50 years. Guys, we were not built to last!
To understand how vascular (blood vessel) disease can cause ED, you need to understand how an erection occurs. During an erection, arteries supplying blood to the penis relax and widen. As the arteries relax, blood floods the penis through two central arteries. These arteries run through two flexible cylinders that run the length of the penis. Thousands of tiny spaces inside these cylinders fill with blood.
At the same time, veins carrying blood away from the penis clamp down. As a result, more blood remains inside the penis. With more blood coming in and less going out, the penis swells and becomes firm. (I’ve put an illustration of this process below.)
Erections depend on the blood vessels that serve the penis. So it’s not surprising that vascular disease, which affects blood vessels, is the leading cause of ED.
The most common type of vascular disease is atherosclerosis, which occurs when fatty deposits build up on artery walls. This narrows and clogs artery walls and limits blood flow through them. Atherosclerosis can occur not only in the arteries of the heart and brain, but also in arteries throughout the body — including those leading to the penis.
Another common cause of ED is diabetes. Men with diabetes are two to three times more likely to experience ED than men without the disease.
Diabetes can cause ED in at least two ways. It can harm the nerves that instruct the arteries in the penis to widen and send more blood. And it can increase a person’s tendency to develop vascular disease, which also restricts blood flow to the penis. High blood pressure and high cholesterol also increase a person’s tendency to develop diseased blood vessels and reduced blood flow.
If your ED is due to vascular disease, taking steps to improve your heart health might also help your ED. These steps include not smoking, exercising regularly, eating a healthy diet and maintaining a healthy weight. Carefully controlling blood sugar, blood pressure and blood cholesterol levels all can help prevent ED.
We have more powerful medicines today to control these conditions than were available when I was a medical student. Yes, some of the blood pressure medicines sometimes can also cause ED. However, making adjustments in these medicines often improves the problem. Finally, we now also have treatments for ED, such as sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra).
In working order
When a man is sexually stimulated, chemical signals from the brain cause the penile arteries to widen, allowing more blood to enter the erectile bodies known as the corpora cavernosa. The tissues swell with blood, causing an erection. At the same time, the blood-engorged tissues compress the veins, keeping blood in the penis and maintaining the erection.