Sexual Health Q&A

How does diabetes lead to erectile dysfunction?

Many diabetics develop neuropathy, atherosclerosis, venous leak, and low testosterone. These conditions can cause erectile difficulties for men.

Neuropathy is a nerve disorder. In normal circumstances, when a man is sexually aroused, a message travels through his nervous system to signal the start of an erection. For a man with neuropathy in his penis, this transmission gets disrupted and the penis does not respond in the typical way.

Experts don’t know why neuropathy occurs in diabetics. Some believe that abnormal proteins formed by high blood sugar cause the nerve damage. Blood sugar could also interfere with message transmission.

Atherosclerosis is a hardening, or thickening, of the arteries. When a man has an erection, his penis fills with blood. Arteries are a critical part of this process, as they expand in response to sexual stimulation and allow blood in. Veins constrict to keep the blood in the penis until the man ejaculates. Then, the blood flows back into the body.

Atherosclerosis makes it difficult for blood to enter the penis. Depending on how severe the condition is, the blood flow may be insufficient for an erection firm enough for sex.

Venous leak occurs when veins are unable to keep enough blood in the penis for a suitable erection.  As noted above, a firm erection results when blood flows into the penis.  Veins normally constrict to keep the blood inside until the man ejaculates.  A venous leak prevents blood from staying in the penis.  Instead, blood leaks back into the body and the erection fails to stay rigid.

Venous leak is often caused by problems with smooth muscle tissue, which needs to relax for a good erection to occur.  Studies have shown that many diabetic men have less smooth muscle content and that this tissue does not always relax properly.

Low testosterone is another common problem for diabetic men.  Testosterone is a sex hormone that affects a man’s sex drive.  Testosterone deficiency can lead to erectile dysfunction.