Peripheral Artery Disease
In the United States, more than 8 million people age 40 and older have peripheral artery disease, or PAD. 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 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 doctor 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.
Explore this Health Topic to learn more about PAD, our role in research and clinical trials, and where to find more information.
Causes - Peripheral Artery Disease
Atherosclerosis is the main cause of PAD.
Plaque buildup in the is called atherosclerosis. 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.
This health topic focuses on PAD in the legs and feet, but other types of PAD block blood flow to the brain, kidneys, or the intestines. A person may have atherosclerosis in just a single artery or in many.
Risk Factors - Peripheral Artery Disease
You may have a higher risk of lower extremity PAD because of your age, family history and , lifestyle habits, other medical conditions, race, ethnicity, and sex. The risk factors for PAD are mostly the same as those for coronary heart disease and carotid artery disease, which are also caused by .
Risk factors that you can change to decrease the chances of getting PAD include smoking, unhealthy blood cholesterol levels, high blood triglycerides, high blood pressure, overweight and obesity, and metabolic syndrome.
You can develop PAD at any age, but your risk goes up as you get older. Most people in the United States who have PAD are age 65 or older.
Worldwide, the age group is younger (ages 45 to 49) in countries with lower incomes, compared to high-income countries.
Family history and genetics
A family history of PAD, heart disease, stroke, or blood vessel disease, such as some types of vasculitis, raises your risk for PAD. Researchers are studying variations that seem to increase the risk of PAD or could make the disease worse.
Genetic studies have found that certain gene variations are found in different types of atherosclerotic diseases, such as PAD, carotid artery disease, and coronary heart disease. An example is the gene variation that’s found in factor V Leiden disorder that increases the risk of .
Over time, unhealthy lifestyle habits can lead to plaque buildup in leg arteries and PAD. These risk factors include:
- Smoking or regularly breathing in secondhand smoke. Tobacco smoke damages your blood vessels, raises your blood pressure, and causes unhealthy cholesterol levels. The nicotine in tobacco also makes your blood vessels tighten and reduces blood flow in your legs. Quitting smoking is a very important action to lower your risk of PAD.
- Not getting enough physical activity can worsen other PAD risk factors.
- Stress, which can make your arteries tighten.
- Unhealthy eating patterns, such as eating foods high in saturated fats. Saturated, or “bad,” fats come from animal sources such as butter, cheese, and fatty meats.
Other medical conditions
Medical conditions that raise your risk of developing PAD include:
- Disorders that cause blood clots, such as thrombocytosis or antiphospholipid antibody syndrome
- Fibromuscular dysplasia, which can cause the artery walls to grow too much, narrowing the artery
- High blood pressure
- Metabolic syndrome
- Unhealthy blood cholesterol levels or high blood triglycerides
Race or ethnicity
African Americans have a higher risk of PAD than people of other races or ethnicities. African Americans are also more likely to have complications of PAD, such as problems walking and loss of a limb.
American Indian women have a higher risk of PAD than white or Asian American women do. Hispanics and Latinos and whites have similar risk levels. However, NHLBI research found that rates of lower extremity PAD are higher among Hispanic and Latino adults who have highly sedentary lifestyles, even without any other risk factors.
Men and women have a similar risk of developing PAD, but PAD affects men and women differently.
Women are more likely than men to have PAD without symptoms. Women also often have more PAD complications, such as problems walking.
Screening and Prevention - Peripheral Artery Disease
Your doctor may ask you questions and check your legs to screen you for PAD if you have risk factors. To prevent PAD, your doctor may talk to you about heart-healthy lifestyle changes and managing medical conditions that may lead to PAD.
Medical history and physical exam
As part of reviewing your medical history, your doctor may ask you about PAD risk factors, your personal and family health history, and whether you have any symptoms of PAD. For example, your doctor may ask whether you have pain or cramps in your legs at rest or during exercise and whether you have any problems with your legs and feet, such as swelling, numbness, or sores that are slow to heal.
Your doctor may also check your legs and feet for pulses, skin conditions, and reactions to pain, temperature, and touch.
How to prevent PAD
To help you prevent PAD, your doctor may talk to you about heart-healthy lifestyle changes and managing conditions that may lead to PAD.
Heart-healthy lifestyle changes include quitting smoking, choosing a heart-healthy eating pattern (such as the DASH eating plan), being physically active, aiming for a healthy weight, and managing stress.
Signs, Symptoms, and Complications - Peripheral Artery Disease
Approximately one in four people with PAD experience common symptoms of PAD. More than half have non-typical symptoms, and about one in five people who have PAD do not report any symptoms. Yet all share high risk of cardiovascular disease. Without treatment, PAD may cause sores, infections and even loss of a limb.
Signs and symptoms
Signs and symptoms of PAD can vary but may include:
- Pain, aching, heaviness, or cramping in your legs when walking or climbing stairs that goes away after rest. This is called intermittent claudication and is the most common PAD symptom. The pain is often in the calf, but you may also feel pain in your buttocks, thigh, or foot.
- Lack of growth of your toenails and leg hair
- One foot feeling colder than the other
- Pale, discolored, or blue leg or foot
- Leg weakness or numbness, which may make you feel off-balance or make it harder to walk
- Pain or a feeling of pins and needles in your leg or foot
- Pain at rest in your leg and foot in severe PAD, which is called critical limb ischemia
- Sores or wounds on your toes, feet, or legs that heal slowly or not at all. The sores may become infected.
Visit Living With to learn how you can help prevent complications.
PAD can lead to complications, including:
- Trouble managing daily activities without help due to reduced mobility.
- Chronic (long-term) poor blood flow in your leg, called critical limb ischemia. Symptoms may include pain during rest. Signs may be sores, infections, and death of tissue () due to lack of blood flow. Gangrene is a severe complication that may require amputation, which is surgical removal of the affected body part.
- Serious infections. If you develop sores on your feet, the sores can get infected. The infection can then spread to your tissues and muscles, to the bone, or into the bloodstream. The risk of these complications is higher for people who have PAD and diabetes. Infections in the foot can usually be treated with antibiotics, but you may have to be treated in the hospital if the infection is severe. Infections in the bloodstream need to be treated right away in the hospital.
- A sudden drop in blood flow to your leg, called acute limb ischemia. This is a serious medical emergency. Call 9-1-1 or seek medical help right away if you suddenly lose feeling in your foot and cannot move it and if it is blue or paler and colder than the other foot. Quick treatment may save your limb.
Learn the warning signs and symptoms of serious complications and what to do.
If you have PAD, you probably have plaque buildup in your other arteries, including arteries in your heart and brain. Over time, plaque buildup can lead to coronary heart disease, heart attack or stroke. If you have PAD, talk to your doctor about ways to lower your risk of these conditions.
Diagnosis - Peripheral Artery Disease
Your doctor will diagnose PAD based on your medical and family history, a physical exam, and the results from tests and procedures.
Medical history and physical exam
To help diagnose PAD, your doctor will want to learn about your signs and symptoms, risk factors, personal health history, and family health history. This discussion may include questions about the following:
- Other medical conditions, including diabetes, heart disease, and chronic kidney disease
- Pain or cramps in your legs while walking or exercising
- Problems with your legs and feet, including swelling, redness, trouble with walking, and wounds that are slow to heal
- Smoking, either currently or in the past
- Your family history of PAD, heart disease, and other blood vessel diseases
During an exam to look for signs of PAD, your doctor will take these steps:
- Check for weak pulses in your legs.
- Listen for poor blood flow in your legs. Your doctor will use a stethoscope to listen for an abnormal whooshing sound, called a bruit.
- Look for problems on your legs and feet, including swelling, sores, or pale skin.
Conditions that can seem like PAD
Some conditions, such as arthritis or problems with the veins, can cause leg pain, but the symptoms are different from PAD. By doing a physical exam and taking your medical history, your doctor can often 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 doctor 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 doctor uses a blood pressure cuff and 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 doctor 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 cholesterol level.
To diagnose PAD, your doctor may also order some of the following tests and procedures:
- Blood tests to check your cholesterol, triglyceride, and blood sugar levels.
- Exercise ABI to show the severity of your leg symptoms and the level of physical activity that produces them. Your doctor will do the ABI test after having you walk on a treadmill. This test may help your doctor diagnose PAD when you have symptoms, but your resting ABI test result is only slightly low. A drop of 20% or more in post-exercise ABI is abnormal.
- Six-minute walking test to measure how far you can walk in a hallway in six minutes. Your doctor may do this test to see how much PAD affects your ability to function and the severity of the PAD.
- Doppler ultrasound to locate areas of reduced blood flow or blockages and measure how fast blood is flowing through the arteries. A handheld device is passed over your skin. A computer converts sound waves into pictures of blood flow in your arteries. Ultrasound can help diagnose PAD and monitor how well PAD treatments have worked.
- Segmental Doppler pressure testing to check different parts of your legs for narrowed or blocked arteries. This test 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.
- Computed tomography angiography (CTA) to see the arteries in your legs and feet. A special dye is injected, then are taken to show the location and extent of any blood vessel blockages.
- (MRA) to examine the structure of your leg arteries. Magnetic resonance angiography may not be safe for people who have metal implants in their body.
- Catheter-based to see inside the arteries of your legs. Your 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, then X-rays are taken. Your doctor 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.
Treatment - Peripheral Artery Disease
Treatment depends on how severe your PAD is and what complications you may develop or may already have. Your treatment plan will be designed to help you reach key goals:
- Reduce your risk of a major health problem such as a heart attack or stroke
- Reduce symptoms of PAD
- Improve your ability to walk, climb stairs, and perform other daily activities
- Lower your risk of losing a limb
- Improve your quality of life
To treat PAD, your doctor may recommend heart-healthy lifestyle changes, an exercise program, medicine, or a procedure to open or bypass blockages in your arteries.
Heart-healthy lifestyle changes
Your doctor may recommend that you adopt lifelong heart-healthy lifestyle changes.
- Quit smoking. Smoking is the main risk factor for PAD. Quitting can reduce your symptoms and your risk of complications. It is also important to avoid secondhand smoke. Visit Smoking and Your Heart and the National Heart, Lung, and Blood Institute’s Your Guide to a Healthy Heart. Although these resources focus on heart health, they include basic information about how to quit smoking. For free help and support to quit smoking, call the National Cancer Institute’s Smoking Quitline at 1-877-44U-QUIT (1-877-448-7848).
- 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 (salt), added sugars, and alcohol.
- Aim for a healthy weight. If you are 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 doctor 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 doctor 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 three times a week and last between 12 and 36 weeks. The most common type of exercise is walking on a treadmill. Other programs may use a device to exercise the upper body. Talk with your doctor about your options for exercise programs.
Home exercise programs
Your doctor 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 doctor will talk with you to help you understand how to do the program. Each exercise session lasts about 30 to 50 minutes. The goal is to work up to at least 30 minutes of continuous walking.
The programs include health coaching or activity monitors. Some home-based programs include regular check-ins with a coach by telephone. Talk with your doctor regularly about your progress.
Your doctor may prescribe medicines to treat PAD and prevent its complications.
- Antiplatelet medicines, such as aspirin or clopidrogrel, to 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. Doctors may also recommend an anticoagulant medicine, or blood thinner, to help prevent blood clots.
- to slow the progression of plaque buildup in the arteries that are causing symptoms and to 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 to 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 doctor may recommend a medical procedure or surgery.
- to open narrowed or blocked arteries. Your 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 of the artery from narrowing again.
- Bypass surgery to treat severe pain, heal wounds, or save a damaged foot or leg when angioplasty is not as likely to work. Your doctor uses one of your other blood vessels or an artificial vessel to create a path around the blocked artery in your leg.
Living With - Peripheral Artery Disease
PAD is a lifelong medical condition. Once you have been diagnosed with PAD, you will need to regularly see a doctor who specializes in vascular (blood vessel) diseases. You will need to take steps to prevent complications. Learn the warning signs of a medical emergency related to PAD, below.
A team of healthcare professionals can help you manage PAD and treat any complications. You may need to see specialists in vascular (blood vessel) medicine, cardiologists to treat heart disease, radiologists to do imaging tests, vascular surgeons to perform procedures to improve blood flow, infectious disease specialists to treat infections, physical therapists to guide your exercise program, podiatrists to provide foot care, and nutritionists to help you plan healthy meals.
Manage your condition
It is important to get routine medical care and to take all medicines as your doctor prescribes.
- Talk with your doctor about how often you should schedule office visits and blood tests or other tests.
- Call your doctor between visits if you start to have leg pain that does not go away after a few minutes of rest or if any other PAD symptoms get worse. Changes in symptoms could be a sign of PAD complications.
- Get recommended vaccines, including the pneumococcus and influenza (flu) shots, every year at the start of flu season. Anyone who lives with you or whom you see often should also get regular vaccines.
Take care of your feet
Foot problems are a common complication of PAD. If you develop a foot sore, you’ll need regular care to help the sore heal and prevent infection.
Many people who have PAD also have diabetes, which raises the risk of complications that may lead to amputation, a type of surgery to remove all or part of a foot or leg. Diabetes may also cause nerve problems that make it hard to sense when you have injured your feet.
You can reduce your risk for foot ulcers and infections by taking care of your feet.
- Always wear socks and shoes. Socks should not have any seams. Wear comfortable shoes that fit well and protect your feet. Your shoes should have low heels and shock-absorbing soles to reduce pressure on the bottom of your foot. Shoes should have fasteners to prevent rubbing. Your doctor may recommend that you visit a specialist who can modify your shoes to reduce your chance of getting sores on your feet.
- Check your feet every day for injuries or sores. If you have PAD and diabetes, have your doctor examine your feet twice a year.
- Do not go barefoot. This will help prevent foot injury that can lead to ulcers and infections, which are more likely when you have poor circulation.
- Follow your doctor’s instructions about caring for incisions (openings) made in the skin of your legs or feet during surgery or a procedure for treating PAD. Return to Treatment to review possible treatment options for PAD.
- See your doctor for any foot problems. Do not treat corns, calluses, long or ingrown nails, or other foot problems yourself to avoid injuries that could lead to sores or infections.
Women and PAD
Certain conditions during pregnancy, such as preeclampsia (a high-blood pressure disorder) or gestational diabetes (high blood sugar during pregnancy), can raise a woman’s risk of developing PAD later in life.
PAD affects women and men differently. Women’s PAD symptoms may be worse than men’s. Women who have PAD often cannot walk as far or as fast as men who have PAD. They also report lower quality of life than men, perhaps because it’s harder to walk and take part in daily activities. Depression is also more common in women who have PAD than in men who have PAD.
Diseases linked with PAD
People who have PAD have lifestyle habits and other factors, such as a family history, that make it more likely that they will develop other diseases related to atherosclerosis, including the following:
- Coronary heart disease, in which plaque builds up in the arteries of the heart
- Diseases that affect the arteries of the brain, including stroke and vascular dementia
- Heart attack
- Carotid artery disease, which affects the arteries in the neck
- Atrial fibrillation, a type of irregular heart rhythm
- Heart failure
- Chronic kidney disease
- Sleep apnea
If you have PAD with symptoms, your doctor may use ultrasound to screen you for abdominal aortic aneurysm.
Control your blood pressure
If you have high blood pressure, it is important that you continue your treatment plan. Following your treatment plan, getting regular follow-up care, and learning how to monitor your condition at home are important. Let your doctor know if you are planning to become pregnant. These steps can help prevent or delay complications that high blood pressure can cause.
Your doctor may adjust your treatment plan as needed to lower or control your high blood pressure.
Follow your diabetes care plan
If you have diabetes, your doctor will recommend lifestyle changes, including a special eating plan, and may prescribe medicines to manage blood sugar levels. Managing diabetes carefully can lower your risk of complications.
Be alert for sores on your feet or legs, and call your doctor if you see signs of a sore getting infected, such as redness, swelling, pain, or pus, or if you have a fever or chills. To treat sores, your doctor may prescribe antibiotics, clean the sores, remove dead tissue with surgery and apply medicines and bandages to the area.
Manage your blood cholesterol levels
If you have unhealthy levels of blood cholesterol, it is important that you continue your treatment. Follow-up care depends on your cholesterol levels, your risk of complications such as a heart attack or a stroke, and your response to treatment.
Take care of your mental health
Living with PAD may cause fear, anxiety, depression, and stress. You may worry about having heart problems or making lifestyle changes that are necessary for your health. Some people become depressed because of problems with walking and daily activities. PAD might also lead to concerns about the risk of amputation.
By lowering stress levels and learning coping skills, you may be able to live longer and improve your quality of life. Talk with your healthcare team about how you feel. Your doctor may recommend you take steps such as these:
- Join a patient support group. This may help you adjust to living with PAD. You can find out how other people manage similar symptoms. Your doctor may be able to recommend local support groups, or you can check with an area medical center.
- Seek support from family and friends. Letting your loved ones know how you feel and what they can do to help you can help relieve stress and anxiety.
- Talk to a professional counselor. If you have depression or anxiety, your doctor may also recommend medicines or other treatments that can improve your quality of life.
Know when to call for help
PAD puts you at high risk of serious health problems. If you think that you are having symptoms of PAD, check with your doctor. For the following conditions, call 9-1-1 right away. Every minute matters.
Acute limb ischemia
Acute limb ischemia is a medical emergency that must be treated rapidly to avoid amputation or other serious problems. Seek medical help right away if:
- You cannot feel or move your foot
- Your leg or foot hurts or feels like “pins and needles” while resting
- One foot is paler or colder than the other
When bacteria enter the blood from an infected sore, they can cause a bloodstream infection. Symptoms include fever and chills. Intravenous (IV) antibiotics need to be given right away in a hospital. If a blood infection is not treated in time, or if the immune system can’t control the infection, the body’s response can lead to septic shock, organ failure, or even death.
If you develop deep ulcers over bones, you are at risk for a bone infection called osteomyelitis. Symptoms include bone pain; excessive sweating; fever and chills; swelling, redness, pain, and warmth at the site of infection; and an open wound that may show pus. Treatment includes antibiotics, surgery to remove infected bone, and procedures to improve blood flow. Treatment may have to be given in a hospital.
Cellulitis is a skin infection that can spread to the deep tissues of the skin and muscle. Symptoms include areas of the skin that are warm, swollen, and tender. Cellulitis can also cause fever, chills, swollen lymph nodes, and blisters.
Your doctor may prescribe antibiotics to take by mouth. If the infection gets worse or if you get very sick, you may need to stay in the hospital for treatment.
Research for Your Health
Improving health with current research
- Peripheral Artery Disease
Learn about the following ways the NHLBI continues to translate current research into improved health for people who have PAD. Research on this topic is part of the NHLBI’s broader commitment to advancing heart and vascular disease scientific discovery and carrying out population and epidemiology studies.
- New Approaches to Treating Severe PAD. Vascular Interventions/Innovations and Therapeutic Advances (VITA) Program is a translational research program to develop promising diagnostics and treatments for blood vessel conditions. One problem with angioplasty is the risk that the blood vessels will scar and re-narrow. A VITA project supported the development of artificial tubes that one day could be used instead of a person’s own blood vessels or ones from a donor during angioplasty. Visit Next-generation replacement blood vessels target kidney and heart disease for more information.
- Identifying Factors That Contribute to Cardiovascular Disease. The NHLBI-funded Multi-Ethnic Study of Atherosclerosis (MESA) aims to identify factors that contribute to heart and blood vessel diseases that occur with or without obvious symptoms. MESA researchers followed a group of study participants for 10 years and found that nearly 5% of them developed PAD. However, participants who scored higher on the American Heart Association’s Life’s Simple 7 checklist for maximizing heart health were less likely to have PAD; their risk decreased about 17% for each of the Life’s Simple 7 criteria they met. Visit Life’s Simple 7 and Peripheral Artery Disease: The Multi-Ethnic Study of Atherosclerosis to learn more.
- Long-Term Smoking Associated with Greater Risk of PAD Compared to Stroke and Coronary Heart Disease. NHLBI-funded research, as part of the Atherosclerosis Risk in Communities (ARIC) study, compared the long-term link between cigarette smoking and PAD, stroke, and coronary heart disease. The study looked at the smoking habits of more than 13,000 people ages 45 to 64 and found that long-term smoking has the greatest effect on a person’s risk of PAD. The results highlight the need to include PAD messaging in programs to help people quit smoking. Visit Cigarette Smoking, Smoking Cessation, and Long-Term Risk of 3 Major Atherosclerotic Diseases to learn more.
- Smoking Linked to Higher Risk of PAD in African Americans. Researchers also looked at the link between smoking and PAD in NHLBI’s Jackson Heart Study. This was the largest single-site study investigating heart and blood vessel disease in African Americans, who have the highest rates of PAD of any group. The study found that the duration and number of cigarettes smoked significantly affect the risk of PAD among African Americans. The study also found that quitting smoking can lower the risk for PAD. Read Smoking linked to higher risk of peripheral artery disease in African-Americans for more information.
Learn about some of the pioneering research contributions we have made over the years that have improved clinical care.
- Addressing gaps in knowledge of PAD and related diseases. In 2012, the NHLBI brought together experts to discuss best practices for surgical and endovascular treatment of peripheral vascular disease. Visit Research Priorities in Treatment of Peripheral Vascular Disease for more information.
- Diabetes—a key risk factor for PAD. The Framingham Heart Study, which began in 1948, led to the discovery that diabetes greatly increases the risk of PAD. The researchers also found that having both diabetes and PAD is a sign of poor blood flow in other arteries, such as those supplying the brain, heart, and arms. For people who have diabetes, the study showed that having PAD is strongly linked with coronary heart disease, heart failure, and stroke. Read Glucose Intolerance, Physical Signs of Peripheral Artery Disease, and Risk of Cardiovascular Events: The Framingham Study to learn more.
- Linking the ankle-brachial index (ABI) to risk of heart and blood vessel diseases. The Cardiovascular Health Study (CHS) is a long-term study of risk factors for heart and blood vessel diseases, including PAD, in older adults. Using data from the study, CHS researchers showed that the lower a person’s ABI score, the greater the risk of heart or blood vessel disease—even before any symptoms appear. The scientists also found that an ABI less than 0.8 was a sign of major blockage in the leg arteries. Visit Ankle-arm index as a marker of atherosclerosis in the Cardiovascular Health Study for more information.
- Making supervised exercise available for people who have PAD. The NHLBI’s Claudication: Exercise Versus Endoluminal Revascularization (CLEVER) study showed that a supervised exercise program was more effective at improving treadmill walking than an angioplasty procedure with stent placement or medicines alone. The results of CLEVER and other research studies led the Centers for Medicare and Medicaid Services to reimburse supervised exercise programs for symptomatic PAD. Read Supervised Exercise vs Primary Stenting for Claudication Resulting from Aortoiliac Peripheral Artery Disease: 6-Month Outcomes from the CLEVER Study to learn more. Also see the National Coverage Determination for more information.
- Supervised treadmill exercise offers multiple benefits for people who have PAD. The NHLBI-supported Treadmill Exercise and GM-CSF Study to Improving Functioning in PAD (PROPEL) showed that stem cell mobilization did not improve walking ability in people who have PAD. However, the study did show that exercise programs helped people walk longer distances and improved the health of the arteries in their arms. Visit Study: Stem cell treatment fails to improve walking impairment in peripheral artery disease for more information.
Advancing research for improved health
- Peripheral Artery Disease
In support of our mission, we are committed to advancing PAD research in part through the following ways.
- We perform research. Our Division of Intramural Research, which includes investigators from the Translational Vascular Medicine Branch and its Experimental Atherosclerosis Laboratory, performs research on PAD.
- We fund research. The research we fund today will help improve our future health. Our Division of Cardiovascular Sciences, which includes the Vascular Biology and Hypertension Branch, oversees much of the research on PAD we fund, helping us to understand, prevent, and manage other conditions. Search the NIH RePORTer to learn about research NHLBI is funding on PAD.
- We stimulate high-impact research. Our Trans-Omics for Precision Medicine (TOPMed) program includes participants who have PAD, which may help us understand how genes contribute to differences in disease severity and how patients respond to treatment. The NHLBI Strategic Vision highlights ways we may support research over the next decade.
Learn about exciting research areas the NHLBI is exploring about PAD.
- Understanding and treating artery stiffness in PAD. The main cause of PAD is atherosclerosis, but NHLBI-funded researchers are exploring the effects of different factors that affect blood flow and stiffness of the arteries in the legs. Researchers are testing the effect of a protein called thrombospondin-1 in human tissues that model PAD. This will help show whether changing artery stiffness could improve symptoms or complications in people who have PAD. Visit Molecular Mechanisms of Flow-Dependent Arterial Remodeling in Peripheral Arterial Disease for more information.
- Exploring the link between diabetes and PAD. Having diabetes increases the risk of both PAD and serious PAD complications, such as critical limb ischemia. Normally, when leg tissues need more oxygen, the body responds by forming new arteries to increase blood flow. We are supporting a study aimed at finding out how diabetes impairs the formation of blood vessels when tissues need more oxygen-rich blood. Visit Role of Endothelial and Progenitor Cell Bioenergetics-Cytoskeletal Machinery in Diabetic Angiopathies for more information.
- Learning about PAD and sleep disorders. The Multi-Ethnic Study of Atherosclerosis (MESA) showed a link between PAD and severe sleep apnea, especially for African Americans. Also, getting too little sleep or sleeping too long may increase risk for PAD. Visit Association of sleep apnea and sleep duration with peripheral artery disease: The Multi-Ethic Study of Atherosclerosis (MESA) to learn more.
Participate in NHLBI Clinical Trials
The National Heart, Lung, and Blood Institute (NHLBI) leads or sponsors many studies aimed at preventing, diagnosing, and treating heart, lung, blood, and sleep disorders.
Trials at the NIH Clinical Center
Evaluating heart conditions
Metabolic or genetic diseases that raise the risk for heart disease
Data and samples from people who have heart or blood vessel disease
To learn more about clinical trials at the NIH Clinical Center or to talk to someone about a study that might fit your needs, call the Office of Patient Recruitment 800-411-1222.
Are you an adult who has PAD and difficulty walking?
Do you need angioplasty to treat PAD?
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Have you been diagnosed with PAD?
Related Health Topics
- Peripheral Artery Disease
- Aim for a Healthy Weight
- Atherosclerosis Risk in Communities (ARIC) Study
- Cardiovascular Health Study
- Coronary Artery Risk Development in Young Adults Study (CARDIA)
- Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents: Full Report
- Framingham Heart Study (FHS)
- Heart and Vascular Diseases
- Jackson Heart Study
- Multi-Ethnic Study of Atherosclerosis (MESA)
- Sleep Deprivation and Deficiency
- Sleep Science and Sleep Disorders
- Strong Heart Study (SHS)
- Systolic Blood Pressure Intervention Trial (SPRINT) Study
- The Heart Truth®
- Trans-Omics for Precision Medicine (TOPMed) Program
- Vascular Dementia: Exercise, Blood Flow, and the Aging Brain
- Women’s Health
- Women’s Health Initiative (WHI)
- Peripheral Artery Disease
- Carotid Artery Disease (NLM, MedlinePlus)
- Diabetes (National Institute of Diabetes and Digestive and Kidney Diseases [NIDDK])
- Dietary Guidelines for Americans 2015–2020, Eighth Edition (U.S. Department of Health and Human Services [HHS] and U.S. Department of Agriculture)
- Hypersensitivity Vasculitis (Allergic Vasculitis) (NLM, MedlinePlus)
- IgA Vasculitis (Henoch-Schönlein Purpura) (NIDDK)
- IgA Vasculitis (Henoch-Schönlein Purpura) (NLM, MedlinePlus)
- Peripheral Arterial Disease (NLM, MedlinePlus)
- Peripheral Arterial Disease Fact Sheet (Centers for Disease Control and Prevention [CDC])
- Physical Activity Guidelines for Americans, Second Edition (HHS)
- Quitting Smoking (CDC)