Peripheral arterial disease, or PAD, reduces blood flow to the arms and legs to such a degree that the person has symptoms. It is most commonly caused by atherosclerosis, or hardening of the arteries.
Atherosclerosis is a condition in which fatty deposits form inside blood vessel walls. This causes the walls to become thick and less elastic. The thickened areas are called plaques. When these plaques grow large enough or break apart, they can block the flow of blood through the arteries. The tissues that receive blood from these arteries then begin to suffer damage from a lack of oxygen. Peripheral arterial disease can also cause symptoms from narrowed arteries to the heart or brain.
Peripheral arterial disease is generally caused by atherosclerosis. Atherosclerosis is caused by an injury to the inside layer of the artery. It usually occurs where the artery bends or branches. Damage to the walls of the artery may be caused by a number of factors, including:
Atherosclerosis is more common in men than in women. A person's risk of atherosclerosis goes up as he or she ages. People who are sedentary are also at higher risk.
PAD may also be caused by a blood clot that lodges in an artery of the arm or leg.
Peripheral arterial disease limits blood flow to the legs and sometimes the arms. Exercise increases the muscle's demand for blood. When the narrowed arteries can't transport enough oxygen-rich blood, the person has a type of pain known as claudication. Claudication generally involves the buttocks, legs, and calves. When the individual rests and the muscle gets enough oxygen, the claudication goes away.
Someone with peripheral arterial disease may also have:
Diagnosis of PAD begins with a medical history and physical exam. The healthcare provider may detect weak or absent pulses in the affected arm or leg. With a stethoscope, the provider can often hear a bruit. A bruit is the sound of blood moving through a narrowed artery. The provider may order a Doppler ultrasound. This special imaging method uses sound waves to detect reduced blood flow through narrow arteries.
If the diagnosis is in doubt or if surgery is being considered, an angiogram may be performed. A contrast agent is injected, and special imaging shows the inside of the affected artery. From this, the provider can determine how narrowed the artery is.
A person may reduce his or her risk for developing atherosclerosis and peripheral arterial disease by:
Over time, PAD can cause loss of sensation or weakness in the affected arm or leg. The artery can become so narrowed that the person has pain at rest. When the artery becomes very narrow or blocked, tissue death can set in. This is known as gangrene. When tissue in the limb begins to die, the limb usually has to be amputated.
Persons with PAD have a risk of heart disease and stroke that is three to six times higher than that of other people.
PAD is not contagious and poses no risk to others.
Exercise can double the amount of exertion a person can take before claudication occurs. Any exercise program should be discussed first with the healthcare provider. In general, someone with PAD should walk 30 minutes a day. The person should walk until the pain is uncomfortable. After a brief rest to allow the pain to go away, the person should continue walking.
Medicines are sometimes helpful in relieving symptoms of PAD. These include:
For severe narrowing of arteries, several procedures are helpful. These include angioplasty, stent placement, and bypass surgery.
Angioplasty is a procedure in which a tube with a balloon is inserted into the blocked artery and inflated. This is 90% successful in reopening the artery and allowing blood to flow. After 5 years, however, almost half of these arteries close up again.
Stents are rigid tubes like tiny drinking straws. They can be placed at the reopened area of the artery and reduce the rate of renarrowing.
Surgery can also be done to bypass the narrowed area. Bypass operations are 70% to 85% successful. Their success depends on which artery is being bypassed and the specific method used to bypass it.
Medicines used to treat PAD may cause nausea, rash, and allergic reactions. Surgery may cause bleeding, infection, and allergic reaction to anesthesia.
If treatment is successful in opening the artery, the individual will have fewer symptoms. However, the problem can recur or develop in other arteries. It is important to work on lowering risk factors for atherosclerosis.
Persons with PAD often need regular visits with the healthcare provider. Any new or worsening symptoms should be reported to the provider.
Author:William M. Boggs, MD
Date Written:
Editor:Crist, Gayle P., MS, BA
Edit Date:06/30/01
Reviewer:Eileen McLaughlin, RN, BSN
Date Reviewed:05/21/01
Scientific American Medicine 2000 (updated monthly); Medical Knowledge Self Assessment Program (MKSAP 11) 1998