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On call: Testing for erectile dysfunction

On call

Testing for erectile dysfunction

Q. When I saw my doctor on my 73rd birthday, my only complaint was that I’ve been having trouble with my erections over the past year. I was surprised that my doctor didn’t do any blood tests beyond the usual battery, and he didn’t refer me to a specialist. Instead, he gave me a prescription for Viagra. The pills are working fine, but should I have tests to find out what’s wrong?

A. In a sense, Viagra’s success is responsible for the brevity of your evaluation. Sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis) all produce good results in about 70% of men, so it’s easy to see why many doctors skip the tests and go straight to treatment. Still, an evaluation is important.

As in so many areas of medicine, the most important step is also the most neglected: Ask the patient. Here are six questions that may tell a lot about the cause of a man’s erectile dysfunction.

1. Do you have good erections at night or when you first awaken in the morning with a full bladder? If nocturnal erections are preserved but sexual intercourse is unsatisfactory, you may be one of the 15% of men with a psychological cause of erectile dysfunction.

2. Do you take any prescription medications or over-the-counter drugs or supplements? Many medications can produce erectile dysfunction in some men; switching medications may clarify the diagnosis — and solve the problem.

3. Do you still have your usual level of sexual desire? If the spirit is willing but the flesh is weak, testosterone deficiency is very unlikely, but if your libido has also waned, a test of hormone levels is important.

4. Do you have any new or progressive urinary tract symptoms? Prostate disease is a rare cause of erectile dysfunction, but if you have new symptoms, a urological evaluation may be in order.

5. Do you smoke, or do you have any symptoms of heart disease, peripheral artery disease, high blood pressure, or diabetes? Good erections depend on healthy blood vessels and nerves in the penis; erectile dysfunction can be the first clue to important systemic disease.

6. How much alcohol do you drink, and do you have any symptoms of liver disease? Erectile dysfunction is one of the many problems associated with alcohol abuse.

Even if the answers don’t suggest any problems, a brief physical exam can be helpful. Your doctor should check for cardiovascular health (blood pressure, leg pulses), obesity (body mass index and abdominal obesity), nerve function (sensation in fingers and toes), and for abnormalities of the prostate and genitals.

Blood tests are also important — but they may not include the special ones you asked about. In fact, the most important tests are cholesterol and blood sugar levels, since erectile dysfunction is often a result of atherosclerosis, diabetes, or both. And since men with erectile dysfunction are at risk for future heart disease, a careful evaluation of your cardiovascular health and cardiac risk factors is essential. In contrast, hormone tests are unlikely to help unless there are clinical clues to possible abnormalities.

What is the actual yield for various tests? To find out, doctors in Australia reviewed the results on 1,455 men with erectile dysfunction. The most common abnormality was the cholesterol profile (15% abnormal). Nearly 13% of the men had abnormal liver function tests. Blood sugar levels were next, with 9% of patients having abnormalities.

In terms of specific problems linked to erectile dysfunction, less than 6% of the men had abnormal testosterone levels; the report does not indicate how many of these were clinically predictable. Other tests that were also once part of a thorough impotence evaluation were even less helpful; prolactin (0.5%), thyroid (0.1%), and iron (1.6%) tests were not cost effective.

All in all, the most important thing a doctor can do in the case of erectile dysfunction is to evaluate his patient’s general health and cardiovascular risks. And the most important thing men can do to prevent the problem is to stay healthy. But if that fails, it’s certainly nice to know that many effective treatments are available.

— Harvey B. Simon, M.D. Editor, Harvard Men’s Health Watch

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Last updated:	August 22, 2006