Peripheral artery disease (PAD)
What is it?
Peripheral artery disease is a common circulatory problem in which narrowed arteries reduce blood flow to your limbs.
When you develop peripheral artery disease (PAD), your extremities — usually your legs — don't receive enough blood flow to keep up with demand. This causes symptoms, most notably leg pain when walking (intermittent claudication).
Peripheral artery disease is also likely to be a sign of a more widespread accumulation of fatty deposits in your arteries (atherosclerosis). This condition may be reducing blood flow to your heart and brain, as well as your legs.
Often, you can successfully treat peripheral artery disease by quitting tobacco, exercising and eating a healthy diet.
While many people with peripheral artery disease have mild or no symptoms, some people have leg pain when walking (intermittent claudication).
Intermittent claudication symptoms include muscle pain or cramping in your legs or arms that's triggered by activity, such as walking, but disappears after a few minutes of rest. The location of the pain depends on the location of the clogged or narrowed artery. Calf pain is most common.
The severity of intermittent claudication varies widely, from mild discomfort to debilitating pain. Severe intermittent claudication can make it hard for you to walk or do other types of physical activity.
Peripheral artery disease symptoms include:
- Painful cramping in your hip, thigh or calf muscles after activity, such as walking or climbing stairs (intermittent claudication)
- Leg numbness or weakness
- Coldness in your lower leg or foot, especially when compared with the other leg
- Sores on your toes, feet or legs that won't heal
- A change in the colour of your legs
- Hair loss or slower hair growth on your feet and legs
- Slower growth of your toenails
- Shiny skin on your legs
- No pulse or a weak pulse in your legs or feet
- Erectile dysfunction in men
If peripheral artery disease progresses, pain may even occur when you're at rest or when you're lying down (ischemic rest pain). It may be intense enough to disrupt sleep. Hanging your legs over the edge of your bed or walking around your room may temporarily relieve the pain.
Peripheral artery disease is often caused by atherosclerosis. In atherosclerosis, fatty deposits (plaques) build up in your artery walls and reduce blood flow.
Although the heart is usually the focus of discussion of atherosclerosis, this disease can and usually does affect arteries throughout your body. When it occurs in the arteries supplying blood to your limbs, it causes peripheral artery disease.
Less commonly, the cause of PAD may be blood vessel inflammation, injury to your limbs, unusual anatomy of your ligaments or muscles, or radiation exposure.
Factors that increase your risk of developing peripheral artery disease include:
- Obesity (a body mass index over 30)
- High blood pressure (140/90 millimeters of mercury or higher)
- High cholesterol (total blood cholesterol over 240 milligrams per deciliter, or 6.2 millimoles per liter)
- Increasing age, especially after reaching 50 years of age
- A family history of peripheral artery disease, heart disease or stroke
- Excess levels of homocysteine, a protein component that helps build and maintain tissue
People who smoke or have diabetes have the greatest risk of developing peripheral artery disease due to reduced blood flow.
If your peripheral artery disease is caused by a buildup of plaques in your blood vessels (atherosclerosis), you're also at risk of developing:
- Critical limb ischemia. This condition begins as open sores that don't heal, an injury, or an infection of your feet or legs. Critical limb ischemia (CLI) occurs when such injuries or infections progress and can cause tissue death (gangrene), sometimes requiring amputation of the affected limb.
- Stroke and heart attack. The atherosclerosis that causes the signs and symptoms of peripheral artery disease isn't limited to your legs. Fat deposits also build up in arteries supplying your heart and brain.
Some of the tests your doctor may rely on to diagnose peripheral artery disease are:
- Physical exam. Your doctor may find signs of PAD during a physical examination, such as a weak or absent pulse below a narrowed area of your artery, whooshing sounds (bruits) over your arteries that can be heard with a stethoscope, evidence of poor wound healing in the area where your blood flow is restricted, and decreased blood pressure in your affected limb.
- Ankle-brachial index (ABI). This is a common test used to diagnose PAD. It compares the blood pressure in your ankle with the blood pressure in your arm. To get a blood pressure reading, your doctor uses a regular blood pressure cuff and a special ultrasound device to evaluate blood pressure and flow. You may walk on a treadmill and have readings taken before and immediately after exercising to capture the severity of the narrowed arteries during walking.
- Ultrasound. Special ultrasound imaging techniques, such as Doppler ultrasound, can help your doctor evaluate blood flow through your blood vessels and identify blocked or narrowed arteries.
- Angiography. By injecting a dye (contrast material) into your blood vessels, this test allows your doctor to view blood flow through your arteries as it happens. Your doctor is able to trace the flow of the contrast material using imaging techniques such as X-ray imaging or procedures called magnetic resonance angiography (MRA) or computerized tomography angiography (CTA). Catheter angiography is a more invasive procedure that involves guiding a catheter through an artery in your groin to the affected area and injecting the dye that way. Although invasive, this type of angiography allows for simultaneous diagnosis and treatment — finding the narrowed area of a blood vessel and then widening it with an angioplasty procedure or administering medication to improve blood flow.
- Blood tests. A sample of your blood can be used to measure your cholesterol and triglycerides and to check for diabetes.