Peripheral artery disease (PAD) is commonly caused by atherosclerosis, which is a buildup of plaque deposited in the walls of blood vessels. These plaques are made of cholesterol, fatty substances, calcium, and other products that can cause the arteries to become stiff and narrowed. This can eventually lead to decreased or completely blocked blood flow to the arms and legs.
The risk factors for developing PAD are similar to those for coronary artery disease (CAD). Those at highest risk for developing PAD are those with diabetes (even borderline) or who have a history of smoking. Many people who have PAD either have diabetes and/or have smoked at some point in their lives. Some people may not even know they have diabetes until they undergo a special blood test to check for it.
Other risk factors for developing PAD include high blood pressure, high cholesterol, kidney disease or CAD. As we age, the likelihood of having PAD also increases.
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Signs & Symptoms
Like chest pain that occurs when blood flow to the heart muscle is compromised, the leg muscles may exhibit symptoms when blood flow is reduced. Claudication—leg cramps in the muscles that occur with activity and improve with rest—occurs because of inadequate blood flow to the leg muscles, such as those in the calf and thighs. Although claudication is the classic symptom of PAD, most will complain of more subtle symptoms such as heaviness in the legs, weakness, or a feeling that the legs may give out.
Standing and resting for a few minutes will cause the symptoms that stopped someone from walking to resolve, as the muscles need less oxygen and nutrition while at rest. While it is safe to begin to walking again, the same cycle of discomfort with walking that resolves with rest will continue.
Over time, people with PAD tend to: limit what they do in order to avoid symptoms, walk slower, or even use a cane. However, they may improve their symptoms by attempting to walk through them.
In its early stages or with mild PAD, there may be minimal physical exam findings. Pulses may be faint or even absent. PAD, when advanced, may be associated with hair loss on the legs and toes, color changes in the skin, loss of feeling and coolness. The skin can become dry and thin over time. Maintaining skin integrity and moisture is important to prevent breakdown, which can be a source of infection.
The color of the skin can vary. It may be pale or appear pink when in a dependent position but can turn white when raised. Dark purple or black areas may develop on the toes when the skin is so deprived of oxygen and nutrients from reduced blood flow that it is dying. Sores can form and can have a difficult time healing when blood flow is minimal, raising the risk of infection. Both sores and infections can threaten the limb if medical attention is not sought.