What Is Peripheral Artery Disease (PAD)?

Peripheral artery disease, or PAD, is a progressive disease that is the result of plaque buildup in the arteries that supply blood to the limbs—usually the legs. Plaque can build up inside arteries around the knee or around the shin and calf. Other common sites for PAD include the arteries in the lower torso or the groin.

PAD is also related to coronary artery disease, or CAD. Not only do PAD and CAD share similar risk factors, they are both caused by atherosclerosis, the buildup of plaque inside arteries. People who have both PAD and CAD have an even higher risk for heart attack and stroke than people with PAD or CAD alone, so it’s important to ask your doctor about getting screened for CAD.

How common is PAD?

PAD affects up to 8.5 million people in the US alone. But studies have shown only about 25% of adults age 50 and older have any awareness of PAD.*

*According to the Centers for Disease Control and Prevention (CDC).

PAD and atherosclerosis

PAD is the end result of atherosclerosis, or hardening of the arteries. This is the process by which the arteries become damaged and inflamed as a result of certain health conditions or risk factors. Then, cholesterol, white blood cells, and other substances build up inside the damaged walls, forming plaque.

Plaque can start forming as early as childhood and builds up slowly, over many years. It may help to imagine plaque as a sticky substance, like sludge on the inside of pipes. However, an important difference is that plaque doesn’t just build up on the interior surface of artery walls—it also builds up inside the walls themselves, causing the arteries to thicken and harden over time.

As atherosclerosis progresses and the areas of plaque grow larger, less blood can get through the arteries to supply your muscles with the oxygen they need to function. This reduced blood flow is what causes symptoms like intermittent claudication, which is pain or cramping in one or both hips, thighs, or calf muscles after walking or being physically active.

PAD and blood clots

People with PAD also have an underlying risk for blood clots that can cause serious blockages in the legs. This is because some plaques, in addition to reducing blood flow through the arteries, can rupture. A ruptured plaque triggers your body’s blood-clotting response. A clot forms around the rupture site, creating a blockage that cuts off blood flow to your legs, causing pain. Though rare, if the blockage is left undetected or untreated, the tissue below a blockage can be deprived of oxygen long enough for gangrene to set in, and may result in amputation.

PAD and cardiovascular health

PAD is such a serious health condition because it involves your cardiovascular system. Cardiovascular means “having to do with the heart and blood vessels."

Your cardiovascular system is also known as your circulatory system, and it connects everything from your brain to your toes. Your heart, arteries, veins, and lungs all work together to move nutrients and oxygen-rich blood to every single part of your body. If you have plaque buildup in your legs, there is a high likelihood that it could occur in other arteries of your body, so it’s important to do everything you can to keep your cardiovascular system healthy.

In addition to following the treatment plan laid out by your healthcare professional, having a heart-healthy lifestyle can help slow the progression of your PAD and lower your risk for other cardiovascular diseases. Learn more about living well with PAD.

Infographic showing the cardiovascular system and how blood flows from the heart to body to lungs