What Causes Peripheral Artery Disease?

When a person has peripheral artery disease (PAD) it means their limbs are not getting enough blood flow. This is because their blood vessels have plaque built up inside them that prevents blood from flowing normally. PAD is also called atherosclerosis or peripheral vascular disease. Sometimes it is referred to as the hardening of the arteries. The plaques that build up in the blood vessels of the arms and legs are the same kinds of plaques that can cause heart attacks or stroke. However, these limb-specific plaques lead to PAD and issues with the arms and legs instead.

Common symptoms of PAD

The most common symptom of PAD is a pain in the arms or legs that gets worse with activity but improves with rest. Someone with PAD might be out running errands all day and have pain in one or both of their calf muscles that gets worse the longer they are on their feet. When they sit down and rest later, the pain gets better. This symptom is called limb claudication.^1-3 About 12 percent of all adults have PAD, with this number increasing to 20 percent for those over seventy years old.^1-2

How does peripheral artery disease develop?

Our arteries are important because they carry blood from our heart and lungs to the rest of our body. This blood from the heart and lungs has lots of oxygen and other important nutrients in it. Normally, this blood flows smoothly, like water through a pipe. However, in some situations, plaques or build-up can develop over time and impede blood flow. This is similar to a pipe or drains getting clogged and water not flowing through it as easily.

The plaques in PAD are made up of cholesterol, fat, inflammation, protein, calcium and other substances that grow along the walls. Eventually, these plaques can get so large that they prevent enough blood from getting through to supply our entire legs or arms. Sometimes, blood clots can form around these plaques, or get stuck within them, reducing blood flow even more.^1-3

What parts of the body does PAD affect?

When there’s not enough blood flow to a certain part of the body, it can be at a higher risk of infection, poor wound healing, or tissue death. This is because nutrients, oxygen, and other important immune system-related cells aren’t getting to these areas as easily. Although the process of plaque development is the same as a heart attack or stroke, PAD is different in that it affects the vessels of the limbs specifically.

Where a person experiences the effects of PAD depends on where plaques have developed and what blood vessels aren’t able to deliver enough blood. For example, if a person has plaque buildup in the popliteal artery behind their knee, they may have issues with their lower leg or their foot, since blood and nutrients are having a harder time getting there. PAD can happen in the arms too, however, this is less common than the legs.^1-3

Does PAD cause heart attacks or stroke?

PAD itself does not cause heart attacks, strokes, or other cardiovascular issues. Blockages in the peripheral arteries will directly affect the limbs, not the heart or the brain. However, if a person has PAD and fatty plaques in their arteries, they may have plaques elsewhere, too. Since these plaques are made in the same way, no matter where in the body they are, it makes sense that having plaques in one place may mean that there are others somewhere else.

Some estimates have suggested that a person with PAD has a 6 to 7 times greater chance of eventually having a heart attack, stroke, coronary artery disease, or transient ischemic attack (TIA, a stroke that resolves within hours).³ This is why people with PAD may be monitored for other similar issues, just like people with heart attacks or stroke might be monitored for PAD.^1-3

Risk factors for peripheral artery disease

Factors that increase the risk of fatty plaque build-up or lead to changes in blood flow can increase the risk that a person will develop PAD. These include, but are not limited to:^1-3

• • High blood pressure
  • High cholesterol
  • Obesity
  • Older age
  • Smoking
  • Kidney disease
  • Family history of heart disease or PAD

If you or a loved one is concerned about having PAD or atherosclerosis in other areas, consult your doctor about ways to reduce your risk.