Peripheral arterial occlusive disease is a condition where blood vessels in the legs become narrowed or blocked, usually because of fatty deposits building up over time. This can lead to pain when walking, skin changes, and serious complications if not treated properly.

How Common Is Peripheral Arterial Occlusive Disease?

Peripheral arterial occlusive disease affects millions of people around the world. In the United States, more than 6.5 million people who are 40 years old or older have this condition. The disease becomes more common as people get older. Among those 60 years and older, between 12% and 20% have the disease, and nearly half of all people 85 years and older are affected.^[1][4][15]

The condition affects men and women, though men are slightly more likely to develop it. Black people face a particularly high risk compared to white people, especially after age 50 in males and age 60 in females. Many people who have peripheral arterial occlusive disease do not realize they have it because they may not experience obvious symptoms, which means the condition often goes unrecognized and untreated.^[5][21]

The global burden of this disease is enormous, with more than 200 million people worldwide living with peripheral arterial occlusive disease. Between 2000 and 2010, the number of people with this condition increased by more than 23%, showing that it is becoming a growing public health concern.^[7][5]

What Causes Peripheral Arterial Occlusive Disease?

The most common cause of peripheral arterial occlusive disease is a process called atherosclerosis, which means the buildup of fatty deposits in the walls of arteries. These deposits are made up of cholesterol and other fatty materials, and they are often referred to as plaque. Over time, plaque gradually narrows the space inside the artery where blood can flow, making it harder for blood to reach the legs and feet.^[1][2]

Arteries are like hollow tubes with a smooth inner lining that allows blood to flow steadily. When plaque builds up on the artery walls, it creates a rough surface and narrows the passageway. Calcium can also accumulate in the blood vessel walls, making the arteries stiff and even narrower. This narrowing restricts blood flow to the muscles and tissues in the legs, especially during physical activity when the body needs more oxygen-rich blood.^[3][5]

Peripheral arterial occlusive disease can develop in two ways: through gradual narrowing of an artery or through sudden blockage. Gradual narrowing usually happens as plaque slowly builds up over many years. Sudden blockage can occur when a blood clot forms in an already narrowed artery, or when a piece of plaque or a blood clot breaks off from somewhere else in the body and travels through the bloodstream until it gets stuck in an artery. When an artery becomes suddenly or completely blocked, the tissue it supplies may not get enough oxygen and could die.^[2][3]

In less common cases, arteries can be narrowed by abnormal muscle growth in the artery wall, inflammation of blood vessels called vasculitis, or pressure from a nearby mass such as a tumor or cyst. Sometimes, a condition called aortic dissection can occur, where the inner layer of the aorta tears and blocks arteries connected to it.^[2][3]

Who Is at Risk for Peripheral Arterial Occlusive Disease?

Several factors increase the risk of developing peripheral arterial occlusive disease. The most significant risk factor is smoking. People who have ever smoked regularly are much more likely to develop this condition. Smoking increases the risk of peripheral arterial occlusive disease fourfold, and it also makes the disease worse once it develops.^[2][7]

Other important risk factors include diabetes, high blood pressure, high cholesterol levels, and high levels of a protein component called homocysteine in the blood. Each of these conditions damages blood vessels over time and contributes to the buildup of plaque in the arteries. Having diabetes that is not well controlled can make symptoms worse and raise the chances of developing other serious cardiovascular problems.^[2][4]

People who are older face a higher risk, as atherosclerosis becomes more common with aging. Those who have obesity, are physically inactive, or have a family history of atherosclerosis or heart disease are also at increased risk. The odds of having peripheral arterial occlusive disease increase with each additional risk factor a person has. For example, having one risk factor increases the odds by about 1.5 times, while having three or more risk factors increases the odds by 10 times.^[2][15]

What Are the Symptoms?

Many people with peripheral arterial occlusive disease have no symptoms at all, especially in the early stages. However, when symptoms do occur, the most common one is leg pain during physical activity that improves with rest. This is called intermittent claudication, a medical term that means “to limp.” The pain typically occurs in the calf muscles, but it can also affect the thighs or buttocks, depending on which artery is blocked.^[1][4]

The pain or discomfort from claudication is caused by muscles not getting enough oxygen-rich blood during exercise. When you walk or climb stairs, your leg muscles need more blood to keep working. If the arteries are narrowed, they cannot deliver enough blood to meet this increased demand, and the muscles start to hurt. The pain usually goes away after resting for a few minutes, which allows the muscles to recover. This stop-and-start pattern is very characteristic of peripheral arterial occlusive disease.^[1][10]

More than half of the artery’s interior usually has to be blocked before symptoms appear. Usually, symptoms occur below the affected artery, so if the blockage is in the thigh area, you might feel pain in the calf. If the blockage is higher up in the pelvis, you might feel pain in the thighs or buttocks.^[2][5]

Other symptoms of peripheral arterial occlusive disease include coldness in the lower leg or foot, especially when one leg feels colder than the other. The skin on the legs might change color, becoming pale, bluish, or shiny. Some people experience numbness or weakness in their legs. Hair growth on the legs and feet may slow down, and toenails may grow more slowly and become brittle. There might be wounds or sores on the feet, legs, or toes that heal very slowly or do not heal at all.^[1][4]

As the disease gets worse, pain can occur even when resting, especially at night when lying flat. This resting pain often happens in the feet or toes and is a sign that the disease has become more severe. Dangling the leg or foot over the edge of the bed may help relieve this pain temporarily. Males might also experience erectile dysfunction if the blockage is in the lower part of the aorta or in the arteries of the pelvis.^[5][9]

In the most severe cases, a condition called critical limb ischemia can develop. This is when blood flow to the leg becomes so restricted that the tissue does not get enough oxygen to survive. Symptoms include severe burning pain that continues even at rest, skin that becomes cold and numb, skin color changes, and wounds that lead to tissue death, known as gangrene. Gangrene can produce a foul smell and requires immediate medical attention, as it may lead to the need for amputation.^[9]

How Can Peripheral Arterial Occlusive Disease Be Prevented?

Preventing peripheral arterial occlusive disease involves making lifestyle changes that keep blood vessels healthy and reduce the buildup of plaque. The single most important thing a person can do is to stop smoking if they smoke. Quitting smoking reduces the risk of the disease developing and prevents it from getting worse in people who already have it. Avoiding secondhand smoke is also important for maintaining vascular health.^[1][12]

Regular exercise is another key way to prevent peripheral arterial occlusive disease. Physical activity helps improve circulation, keeps blood vessels flexible, and reduces many risk factors such as high blood pressure and high cholesterol. Walking is one of the best exercises because it directly benefits the legs. Even moderate amounts of regular exercise can make a significant difference in vascular health.^[4][21]

Eating a heart-healthy diet is also crucial for prevention. A diet that includes plenty of fruits, vegetables, whole grains, and lean proteins supports vascular health. Limiting foods high in saturated fats, trans fats, sodium, and added sugars helps prevent plaque buildup in the arteries. Some people find that following eating patterns like the Mediterranean diet, which emphasizes whole foods and healthy fats like olive oil, can help lower cholesterol and keep blood sugar levels stable.^[12][21]

Maintaining a healthy weight is important because carrying excess weight increases the risk of developing conditions like diabetes, high blood pressure, and high cholesterol, all of which contribute to peripheral arterial occlusive disease. Losing even a small amount of weight, such as 3% to 5% of current body weight, can help manage these risk factors and improve overall health.^[12]

Managing other health conditions is also essential for prevention. This means keeping blood pressure under control, managing cholesterol levels, and keeping blood sugar levels in a healthy range if you have diabetes. Regular check-ups with a healthcare provider can help monitor these conditions and adjust treatments as needed.^[4][22]

How the Body Is Affected by Peripheral Arterial Occlusive Disease

Peripheral arterial occlusive disease affects the body by limiting the amount of oxygen-rich blood that reaches the legs and feet. Normally, blood flows freely through the arteries, delivering oxygen and nutrients to muscles and tissues. When plaque builds up in the artery walls, it narrows the space where blood can flow, making it harder for blood to get through. This inadequate blood supply leads to a condition called ischemia, which means tissues are not getting enough oxygen.^[2][3]

Ischemia can develop gradually as plaque slowly accumulates over many years, or it can happen suddenly if a blood clot forms and blocks the artery. When muscles do not receive enough oxygen, they cannot work properly, which is why people experience pain and cramping during physical activity. The pain forces people to stop and rest, giving the muscles time to recover with the limited blood flow available.^[2]

As the disease progresses, the reduced blood flow affects not just the muscles but also the skin, nerves, and other tissues in the legs and feet. The skin may become pale or bluish because it is not receiving enough oxygenated blood. It may also feel cold to the touch. Hair follicles and nail beds need a steady supply of nutrients to grow, so when blood flow is reduced, hair growth slows down and nails become brittle.^[1][4]

In severe cases, when blood flow becomes critically low, tissues begin to die. This can lead to open sores or ulcers that do not heal because the body cannot deliver the nutrients and immune cells needed for wound healing. If tissue death continues, gangrene can develop, which is a serious and potentially life-threatening complication. Gangrene requires urgent medical treatment and may result in the need to remove the affected tissue or limb.^[9]

Peripheral arterial occlusive disease also has effects beyond the legs. Because atherosclerosis is a disease that affects blood vessels throughout the body, people with this condition are at higher risk of developing blockages in other important arteries, such as those supplying the heart and brain. This increases the risk of heart attacks and strokes. The same processes that narrow the arteries in the legs are likely happening in other parts of the body, which is why peripheral arterial occlusive disease is considered a marker for overall cardiovascular health.^[1][9]