Erectile dysfunction (ED) may be the first sign of impending cardiovascular troubles, say experts. And while anti-impotence drugs can help to treat your problems in the bedroom, taking these pills without evaluating your heart may spell big trouble for your health.

Scientists are now discovering that erectile dysfunction may serve as an early warning sign for angina, heart disease and stroke.

"Erectile dysfunction is frequently a manifestation of underlying cardiovascular problems." says Dr. Andrew McCullough, director of male sexual health, fertility and microsurgery at New York University School of Medicine.

While the connection may be no surprise to some, as anti-impotence drugs, like Viagra and Cialis, were first studied as cardiovascular treatments, doctors are only recently beginning to understand the true connection between erectile dysfunction and cardiovascular disease.

Finding The Link
Erectile problems may be caused by psychological obstacles, such as "performance" anxiety, but many more cases are the result of physical issues caused by arteries that do not expand well and prevent sufficient blood flow to the penis needed to create an erection.

"We know that up to 90 percent of patients with ED have a vascular cause." says Dr. Alan Bank, medical director of research at St. Paul Heart Clinic in Minnesota.

This correlation was first seen to be strongest in patients with erectile dysfunction and type 2 diabetes, a one-two punch in terms of cardiac risk. As researchers found in a 2003 study published in Circulation, almost 40 percent of men with type 2 diabetes and silent coronary artery disease also had some degree of erectile dysfunction, compared to only 5 percent of diabetic men without coronary artery disease.

Sometimes, however, the cardiac problems associated with erectile dysfunction aren’t seen until much later.

For example, in a July 2005 study published in European Urology, researchers found that men with moderate-to-severe erectile dysfunction had a greater risk of stroke over the course of 10 years when compared to those who had no erectile problems.

When to Call the "Plumber"—a Cardiologist
Whether the erectile problems are seen with or precede heart trouble seems to come down to a matter of plumbing, explains McCullough.

"If you turn on your kitchen faucet and you don’t get any flow, either the faucet is broken or the pipes are clogged." he says. This means that erectile dysfunction is either caused by a problem directly related to the penis—the "faucet"—or to the blood vessels—the "pipes"—leading to the penis.

This latter explanation of "pipe clogging" seems to explain why heart problems and erectile dysfunction are so often seen together.

High levels of cholesterol or arterial damage can cause arteries to clog. As a result, there is not enough blood flow to the penis during sexual stimulation, which can cause impotence.

If it’s not a matter of "clogged pipes." then it’s time to look to the "faucet" for the source of the problem. And when the cause of erectile dysfunction is a problem within the penis itself, the cause is probably more subtle than clogged arteries.

Sexual Troubles that Precede Heart Disease
In a review of recent studies, published in July 2005 in The American Journal of Cardiology, researchers note the increasing evidence that erectile dysfunction may be caused by a reduced amount of nitric oxide in the blood vessels of the penis.

As the demand for blood flow to the penis increases during sexual activity, nitric oxide is released by the body to help the blood vessels expand. In men with erectile dysfunction, nitric oxide levels are low, so blood vessels cannot expand to allow the additional blood to reach the penis. Drugs like Viagra are so useful, says Bank, because they work along the same pathway that increases the amount of nitric oxide in the body.

But low levels of nitric oxide can affect more than just sexual health; nitric oxide also acts to keep blood vessels flexible by resisting atherosclerosis, or hardening of the arteries from cholesterol deposits. So, a reduced amount of this substance can also signal future cardiac troubles.

Instead of just getting a prescription to treat their condition, experts recommend that men with erectile dysfunction see a doctor who can check for underlying vascular problems.

"Men with erectile difficulties should stop and consider the possible underlying cause of that dysfunction." says McCullough.