Coronary artery bypass graft (CABG) is a big operation. Any major surgery might contribute to erectile dysfunction (ED). But there are other reasons you should consider.

CABG patients typically need many medicines. And some common heart drugs can cause ED. But don’t stop these meds on your own. Instead, ask your doctor if a careful drug change is worth a try.

There is also a more basic reason that CABG patients may have ED. The operation is performed to bypass arteries that are damaged by atherosclerosis (commonly called “hardening of the arteries”). This same process is also the leading cause of ED.

ED and heart disease are as different as night and day. So why do they strike together so often?

The two conditions share common risk factors. For years, doctors have known the major heart risk factors: advanced age, smoking, abnormal cholesterol levels, high blood pressure, diabetes, physical inactivity and obesity. More recently, it’s become clear that those exact traits also contribute to ED.

All arteries in the heart, the penis, and the rest of the body have a thin inner lining of cells. These cells make nitric oxide, a tiny chemical that helps keep the artery’s lining smooth and healthy. Atherosclerosis damages the lining, lowering the supply of nitric oxide.

Nitric oxide relaxes artery walls. It helps the heart by making it easier for letting the heart muscle get more oxygen-rich blood when it’s working hard. And it helps the penis, since a good erection requires a big increase in the amount of blood in the organ. Nitric oxide has a crucial role, too. It helps nerve cells “talk” with one another, so the impulses of desire can communicate with the arteries of the penis.

If risk factors cause these problems, can correcting them help? In the case of both heart disease and ED, the answer is yes. Men that stop smoking, improve their cholesterol, lower high blood pressure, control diabetes, shed extra pounds, and take up exercise can expect impressive protection against coronary artery disease. New evidence suggests the same changes may also help correct ED.