Peripheral Artery Disease
In the United States, more than 8 million people ages 40 and older have peripheral artery disease, or PAD. Also called peripheral arterial disease, PAD is caused by atherosclerosis, or plaque buildup, that reduces the flow of blood in peripheral arteries — the blood vessels that carry blood away from the heart to other parts of the body. This health topic focuses on the most common type of PAD, called “lower extremity PAD,” which reduces blood flow to the legs and feet.
You may have lower extremity PAD if you have muscle pain or weakness that begins with physical activity, such as walking, and stops within minutes after resting. About 1 in 4 people who have PAD experience these symptoms. But you may experience other symptoms or no symptoms at all. If you smoke or have high blood pressure or other risk factors for PAD, even without symptoms, ask your healthcare provider about getting tested. It is important to be aware that if you have lower extremity PAD, you may also have plaque buildup in other arteries leading to and from your heart and brain, putting you at higher risk of stroke or heart attack.
Early diagnosis and management of PAD can help treat your symptoms and reduce your risk for serious complications.
What causes PAD?
Atherosclerosis is the main cause of PAD.
Atherosclerosis is a disease in which a waxy substance called plaque builds up on the inner lining of arteries. Plaque is made up of fat, cholesterol, fibrous tissue, and calcium. In PAD, plaque may reduce or fully block the flow of oxygen-rich blood through arteries to the body’s vital organs and the limbs.
About 1 in 4 people with PAD experience common symptoms of the condition. More than half have nontypical symptoms, and about 1 in 5 people who have PAD do not report any symptoms. No matter the symptoms, everyone with PAD shares the same high risk of cardiovascular disease. Without treatment, PAD may cause sores, infections, and even the loss of a limb.
Symptoms of PAD can vary, but there are a few common ones.
- Pain, aching, heaviness, or cramping in your legs that comes when walking or climbing stairs and goes away after rest is called intermittent claudication. It is the most common PAD symptom. The pain is often in the calf, but you may also feel it in your buttocks, thigh, or foot.
- Your toenails and leg hair may stop growing. Advertisement
- One foot may feel colder than the other.
- Your foot or leg may become pale, discolored, or blue.
- Leg weakness or numbness may make you feel off-balance or make it harder to walk.
- You may have pain or a feeling of pins and needles in your leg or foot.
- In severe PAD, pain in your leg and foot when at rest is called critical limb ischemia.
- Sores or wounds on your toes, feet, or legs may appear, may heal slowly, or may not heal at all. The sores may become infected.
Conditions that can seem like PAD
Some conditions, such as arthritis or vein problems can cause leg pain, but the symptoms are different from those for PAD. A physical exam and your medical history can help your provider rule out these conditions.
However, problems with nerves can cause pain that may be confused with PAD. Sometimes a nerve is squeezed where it exits the spinal column. The result is pain that radiates, or spreads, from the hips or buttocks and down the leg.
To confirm that your pain is the result of PAD, your provider may ask you to stand up or change your position. Those movements often trigger nerve-related pain. In contrast, PAD pain is often brought on by leg exercise and is quickly relieved by rest with no need to change position.
Diagnostic tests and procedures
The ankle-brachial index (ABI) test is usually the first test used to diagnose PAD. The test compares blood pressure in your ankle with the blood pressure in your arm. Your provider uses a blood pressure cuff and ultrasound device for this painless test.
A healthy ABI result is 1.00 or greater. If you have an ABI of less than 0.90 while resting, you may have PAD. An ABI of less than 0.40 is a sign of severe PAD. If there are problems with the arteries in your ankle, your provider may do a toe-brachial index (TBI) test instead, which measures the blood pressure in your big toe. A TBI less than 0.7 is abnormal. Be aware of your ABI, just as you know and keep track of your blood pressure numbers.
To diagnose PAD, your provider may also order some of the following tests and procedures:
- Blood tests check your cholesterol, triglyceride, and blood sugar levels.
- An exercise ABI test shows the severity of your leg symptoms and the level of physical activity that produces them. Your provider will do the ABI test after having you walk on a treadmill. This test may help them diagnose PAD when you have symptoms but your resting ABI test result is only slightly low. A drop of 20% or more in a post-exercise ABI is abnormal.
- A 6-minute walking test measures how far you can walk in a hallway in 6 minutes. Your provider may do this test to see how much PAD affects your ability to function and how serious your PAD is.
- Doppler ultrasound locates areas of reduced blood flow or blockages and measures how fast blood is flowing through the arteries. A handheld device is passed over your skin, and a computer converts sound waves into pictures of the blood flow in your arteries. Ultrasound can help diagnose PAD and monitor how well treatments for the condition have worked.
- Segmental Doppler pressure testing checks different parts of your legs for narrowed or blocked arteries. This method is similar to ABI testing but uses blood pressure cuffs placed at thigh, calf, and ankle levels. The ultrasound device amplifies the sounds of blood flow in your arteries, making it easier to measure the blood pressure in these areas of your leg.
Your provider may also order an imaging test using angiography to get a better picture of the blood vessels in your legs and feet. There are several types of angiography:
- Computed tomography angiography (CTA) allows providers to see the arteries in your legs and feet. A special dye is injected, and then X-rays are taken to show the location and extent of any blood vessel blockages.
- Magnetic resonance angiography (MRA) examines the structure of your leg arteries. MRA tests may not be safe for people who have metal implants in their body.
- Catheter-based angiography lets providers see inside the arteries of your legs. A doctor inserts a catheter, or tube, into an artery in your groin and guides it to the affected area. A special dye is released through the catheter and then X-rays are taken. Your provider may suggest this procedure for serious pain in the legs or feet or when treatments for PAD have not worked or other testing has not been helpful.
Your provider may recommend that you adopt lifelong heart-healthy lifestyle changes:
- Quit smoking. Smoking is the main risk factor of PAD. Quitting can reduce your symptoms and your risk of complications. It is also important to avoid secondhand smoke.
- Choose heart-healthy foods, such as those in the DASH eating plan. A heart-healthy eating plan includes fruits, vegetables, and whole grains and limits saturated fats, sodium, added sugars, and alcohol.
- Aim for a healthy weight. If you have overweight, losing just 3% to 5% of your current weight can help you manage some PAD risk factors, such as high blood cholesterol and diabetes. Losing even more weight can lower your blood pressure.
- Get regular physical activity. Staying physically active can help you manage PAD risk factors such as high blood cholesterol, high blood pressure, and overweight or obesity. Before starting any exercise program, ask your provider what level of physical activity is right for you.
- Manage stress. Learning how to manage stress, relax, get good-quality sleep, and cope with problems can improve your emotional and physical health.
Physical activity often works well to relieve PAD symptoms and improve your ability to walk and carry out daily activities. Regular physical activity can improve the circulation in your legs. Exercise can reduce inflammation and help your blood vessels work better.
Your provider may recommend a supervised exercise program that takes place in a clinic or a hospital. The exercise program may be part of a more complete cardiac rehabilitation program.
PAD exercise programs usually meet at least 3 times a week and last between 3 months and 9 months. The most common type of exercise in these programs is treadmill walking. Other programs may use a device to exercise the upper body. Talk with your provider about your options for exercise programs.
Home exercise programs
Your provider may recommend a home-based exercise program with coaching that is similar to a supervised exercise program in a clinic. Home-based programs usually involve walking outside instead of on a treadmill. Your provider will talk with you to help you understand how to follow the program. Each exercise session lasts 30 to 50 minutes. The goal is to work up to at least 30 minutes of continuous walking.
These programs include health coaching or activity monitors. Some home-based programs include regular check-ins with a coach by telephone. Talk with your provider regularly about your progress.
Your provider may prescribe medicines to treat PAD and prevent complications. These may include:
- Antiplatelet medicines, such as aspirin or clopidogrel, prevent blood clots from forming and narrowing the arteries even further. These medicines also lower the risk of heart attack or stroke. Possible side effects include bleeding or an allergic reaction. One type of antiplatelet medicine, cilostazol, may also improve your symptoms and make walking easier. Possible side effects of cilostazol include headache, diarrhea, heart palpitations, and dizziness. Providers may also recommend an anticoagulant medicine, Advertisement
- Statins lower cholesterol and certain fats in the blood, and can slow the progression of plaque buildup in the arteries that is causing symptoms. Statins also lower your risk of complications from PAD. Side effects are rare but may include muscle pain or damage.
- ACE inhibitors and angiotensin II receptor blockers (ARBs) or other medicines lower blood pressure and prevent blood vessels from narrowing.
Procedures or surgery
If lifestyle changes, an exercise program, and medicines do not work well enough, your provider may recommend a medical procedure or surgery.
- Angioplasty is a procedure to open narrowed or blocked arteries. The doctor may inflate a small balloon in the artery to flatten the plaque. Sometimes the balloon is coated with medicine to help the artery heal. Your doctor may also insert a small mesh tube called a stent to reduce the chances that the artery will narrow again.
- Bypass surgery may be used to treat severe pain, heal wounds, or save a damaged foot or leg when angioplasty is not as likely to work. In this procedure, your surgeon uses a piece of another blood vessel from your body or an artificial vessel to create a new path around a blocked artery in your leg.