What Is Peripheral Arterial Disease?
Peripheral arterial disease (PAD) occurs when a
fatty material called plaque (plak) builds up on the inside walls of the
arteries that carry blood from the heart to the head, internal organs, and
limbs. PAD is also known as atherosclerotic peripheral arterial disease.
The buildup of plaque on the artery walls is called
atherosclerosis
(ath-er-o-skler-O-sis), or hardening of the arteries. Atherosclerosis causes
the arteries to narrow or become blocked, which can reduce or block blood flow.
PAD most commonly affects blood flow to the legs.
Blocked blood flow can cause pain and numbness. It
also can increase a person's chance of getting an infection, and it can make it
difficult for the person's body to fight the infection. If severe enough,
blocked blood flow can cause tissue death (gangrene). PAD is the leading cause
of leg amputation.
The illustration shows the location
of leg arteries that can be affected by peripheral arterial disease. Figure A
shows a normal artery with normal blood flow (the inset image shows a
cross-section of the normal artery). Figure B shows an artery with plaque
buildup, which is partially blocking blood flow (the inset image shows the
degree to which the artery is blocked).
Important General Information
Atherosclerosis can affect arteries anywhere in the
body, including the arteries that carry blood to the heart and brain. When
atherosclerosis affects the arteries of the heart, it is called
coronary
artery disease (CAD). CAD can cause a
heart
attack. If atherosclerosis is in the limbs, it also is likely to be in the
coronary arteries.
When atherosclerosis affects the major arteries
supplying the brain, it is called carotid artery disease. Carotid artery
disease can cause a
stroke.
PAD (atherosclerosis in the arteries that supply
blood to the limbs, especially the legs) is a common, yet serious disease. Men
are more likely to have symptoms of PAD, but both men and women can develop the
disease. PAD can impair physical health and diminish the ability to walk.
In the advanced stages of PAD, blood flow to one or
both legs can be completely or mostly blocked. This is known as chronic
critical limb ischemia (CLI). A very severe blockage in the legs and feet means
that the legs do not receive the oxygen or nutrition needed for cellular or
skin growth and repair. CLI may lead to painful leg or foot sores, and it could
eventually lead to gangrene. If this condition is left untreated, the foot or
leg may need to be amputated.
Outlook
A person with PAD has a six to seven times greater
risk of CAD, heart attack, stroke, or transient ischemic attack ("mini stroke")
than the rest of the population. If a person has heart disease, he or she has a
1 in 3 chance of having blocked arteries in the legs. Early diagnosis and
treatment of PAD, including screening high-risk individuals, are important to
prevent disability and save lives. PAD treatment may stop the disease from
progressing and reduce the risk of heart attack, heart disease, and stroke.
Although PAD is serious, it is treatable. The
buildup of plaque in the arteries can often be stopped or reversed with dietary
changes, exercise, and efforts to lower
high
cholesterol levels and
high
blood pressure. In some patients, blood flow in the vessels may be improved
by medicines or surgery.
Other Names for Peripheral Arterial Disease
- Atherosclerotic peripheral arterial disease
- Peripheral vascular disease (PVD)
- Vascular disease
- Hardening of the arteries
- Claudication
- Poor circulation
- Leg cramps from poor circulation
What Causes Peripheral Arterial Disease?
The most common cause of peripheral arterial disease
(PAD) is
atherosclerosis.
When atherosclerosis affects the arteries of the limbs, it is called PAD. The
exact cause of atherosclerosis is unknown in the majority of cases. In
atherosclerosis, the plaque that builds up on artery walls is made up of fat,
cholesterol, calcium, and other substances in the blood.
Smoking,
diabetes, a
high
blood cholesterol level, and
high
blood pressure increase the risk of atherosclerosis.
Who Is At Risk for Peripheral Arterial
Disease?
Peripheral arterial disease (PAD) affects 8 to 12
million people in the United States. An estimated 5 percent of U.S. adults over
age 50 have PAD. Among adults age 65 and older, 12 to 20 percent may have
PAD.
Major Risk Factors
Major risk factors for developing PAD include:
- Smoking. Smoking is more closely related to
developing PAD than any other risk factor. Smoking increases the risk of
developing PAD three to five times. On average, smokers who develop PAD
experience symptoms 10 years earlier than nonsmokers who develop PAD. Stopping
smoking will slow the progress of PAD. Smoking even one or two cigarettes daily
can interfere with the treatment for PAD. Smokers and diabetics have the
greatest risk of complications from PAD, including gangrene in the leg from
decreased blood flow.
- Chronic or serious illnesses, such as diabetes.
One in three people over age 50 with diabetes is likely to have PAD. Anyone
over age 50 with diabetes should be screened for PAD.
- Other diseases and conditions, such as:
- Kidney disease
- High blood pressure or a family history of it
- A high cholesterol level or a family history
of it
- Heart disease or a family history of it
- A family history of
stroke
- Age. Men who are older than age 50 and women who
are older than age 55 are at higher risk for PAD.
What Are the Signs and Symptoms of Peripheral
Arterial Disease?
At least half of the people who have peripheral
arterial disease (PAD) don't have any signs or symptoms of the disease.
People who do have signs or symptoms may have pain
when walking or climbing stairs, which may be relieved after resting. This pain
is called intermittent claudication (klaw-de-KA-shen). Blood brings oxygen to
the muscles, but during exercise, muscles need more blood flow. If there is a
blockage in the blood vessels, muscles won't get enough blood. If a person has
intermittent claudication and exercises while in pain, his or her muscles may
be harmed. When resting, the muscles require less blood flow and the pain goes
away. Claudication is more likely in people who also have atherosclerosis in
other arteries, such as the heart and brain. About 10 percent of people with
PAD have intermittent claudication.
Other signs and symptoms of PAD include:
- Pain, numbness, aching, and heaviness in the
muscles
- Cramping in the legs, thighs, calves, and
feet
- A weak or absent pulse in the legs or feet
- Sores or wounds on toes, feet, or legs that heal
slowly, poorly, or not at all
- Color changes in skin, paleness, or blueness
(called cyanosis)
- A decreased temperature in one leg compared to
the other leg
- Poor nail growth and decreased hair growth on
toes and legs
- Erectile dysfunction, especially among people
with diabetes
How Is Peripheral Arterial Disease Diagnosed?
Peripheral arterial disease (PAD) is diagnosed based
on general medical and family history, history of leg or heart problems,
personal risk factors, a physical exam, and test results. An accurate diagnosis
is critical, because people with PAD face a six to seven times higher risk of
heart disease or
stroke than the rest of the population. PAD is often diagnosed
after symptoms are reported. If you have PAD, your doctor also may want to look
for signs of
coronary
artery disease (CAD).
Specialists Involved
Mild PAD may be managed by a primary care doctor,
internist, or general practitioner. For more advanced PAD, a vascular
specialist (a doctor who specializes in treating blood vessel problems) may be
involved. A cardiologist (a doctor who specializes in heart diseases) also may
be involved in the care of patients with PAD.
Medical and Family History
Medical and family history is important in
diagnosing PAD. Your doctor may:
- Ask about your family history of cardiovascular
disease
- Review your medical history, including
high
blood pressure or
diabetes
- Ask about any symptoms, including any symptoms
that occur when walking or exercising
- Ask if you are currently or used to be a smoker
- Ask if you have any symptoms in the legs when
sitting, standing, walking, or climbing
- Review your diet
- Review your current medicines
Physical Exam
The physical exam may involve:
- Checking blood flow in your leg or foot to see if
the pulse is either weak or absent.
- Checking pulses in your leg arteries for an
abnormal whooshing sound called a bruit (broo-E). A bruit can be heard with a
stethoscope and may be a warning of a narrow or blocked section of an
artery.
- Checking for poor wound healing.
- Comparing blood pressure between your limbs to
see if blood pressure is lower in the affected limb.
- Checking hair, skin, and nails for any changes
that may indicate PAD.
Diagnostic Tests and Procedures
A simple test called an ankle-brachial index (ABI)
can be used to diagnose PAD. The ABI compares blood pressure in the ankle with
blood pressure in the arm to see how well blood is flowing. A normal ABI is 1.0
or greater (with a range of 0.90 to 1.30). The test takes about 1015
minutes to measure both arms and both ankles. It can help the doctor find out
if PAD is affecting the legs, but it will not identify which blood vessels are
blocked. The ABI can be performed yearly if necessary to see if the disease is
getting worse.
The illustration shows the
ankle-brachial index (ABI) test. The ABI gives the ratio of the systolic blood
pressure in the ankle to the systolic blood pressure in the brachial artery of
the arm.
A
Doppler ultrasound is a test that uses sound waves to tell
whether a blood vessel is open or blocked. This test uses a blood pressure cuff
and special device to measure blood flow in the veins and arteries in the arms
and legs. The Doppler ultrasound can help to determine the level and degree of
PAD.
A treadmill test will provide more information on
the severity of the symptoms and the level of exercise that provokes symptoms.
For this test, you will walk on a treadmill, which will help identify any
difficulties that you may have during normal walking.
A magnetic resonance angiogram (MRA) uses radio wave
energy to take pictures of blood vessels inside the body. MRA is a type of
magnetic resonance imaging (MRI) scan. An MRA can detect problems that may
cause reduced blood flow in the blood vessels. It can determine the location
and degree of blockage. A patient with a pacemaker, prosthetic joint, stent,
surgical clips, mechanical heart valve, or other metallic devices in his or her
body might not be eligible for an MRA depending on the type of metallic
device.
An arteriogram is a "road map" of the arteries used
to pinpoint the exact location of the blockage in a limb. An
x ray is taken after injecting dye through a needle or
catheter into an artery. When the dye is injected, the patient may feel mildly
flushed. The pictures from the x ray can determine the location, type, and
extent of the blockage. Some hospitals are using a newer method that uses tiny
ultrasound cameras to take pictures inside the blood vessel.
Blood tests may be done to check the patient's blood
sugar level to screen for diabetes. Blood tests also may be used to check the
patient's cholesterol levels.
How Is Peripheral Arterial Disease Treated?
Goals of Treatment
The overall goals for treating peripheral arterial
disease (PAD) are to reduce symptoms, improve quality of life, and prevent
complications. Treatment is based on symptoms, risk factors, physical exam
results, and diagnostic tests.
Specific Types of Treatment
Specific treatments for PAD include lifestyle
changes, medicines, and surgery or special procedures.
Lifestyle Changes
Treatment often includes making long-lasting
lifestyle changes, such as:
Talk with your doctor about participating in a
supervised exercise therapy program. Follow a low-saturated fat,
low-cholesterol diet, and eat foods with less salt, total fat, and saturated
fat. Eat more fruits, vegetables, and low-fat dairy products. If you are
overweight or obese, work with your doctor to develop a reasonable weight-loss
plan. If you are diabetic or at risk for critical limb ischemia, have your feet
examined regularly.
Medicines
Medicines may be prescribed to:
- Lower high cholesterol levels and high blood
pressure
- Thin the blood to prevent clots from forming due
to low blood flow
- Dissolve blood clots
- Help improve pain in the legs that is the result
of walking or climbing stairs (claudication)
Some medicines lower the level of low density
lipoprotein (LDL) cholesterol. LDL is the "bad" cholesterol. The higher the LDL
level in the blood, the greater the chance of heart disease. Medicines may
include statins, such as lovastatin, simvastatin, pravastatin, fluvastatin, and
atorvastatin. Other medicines may include ezetimibe, gemfibrozil, and certain
binding agents.
Blood pressure should be lowered if it is too high.
Treatment should aim for a blood pressure lower than 130/80 mmHg. Many
medicines are available to lower blood pressure, such as angiotensin-converting
enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), beta-blockers,
diuretics ("water pills"), and calcium channel blockers.
Anticoagulants or blood thinners may be prescribed
to prevent clots in the arteries. Thrombolytic therapy involves clot-dissolving
drugs inserted into an artery to break up a blood clot. To stop platelets from
clumping together, antiplatelet drugs such as clopidogrel
(Plavix®) and aspirin may be prescribed. To help increase
distances walked without pain and help improve claudication, pentoxifylline
(Trental®) or cilostazol (Pletal®) may be
prescribed.
Surgeries or Special Procedures
Surgery may be necessary if blood flow in a limb is
completely or almost completely blocked. In bypass grafting surgery, the doctor
uses a blood vessel from another part of your body or a tube made of synthetic
(man-made) material to make a graft. This graft bypasses the blockage in the
artery, allowing blood to flow around it. Surgery does not cure PAD, but it may
increase blood flow to the limb.
Angioplasty
(AN-jee-oh-plas-tee) may be performed to restore blood flow through a narrowed
or blocked artery. During the procedure, a thin tube (catheter) is inserted
into a blocked artery and a small balloon on the tip of the catheter is
inflated. When the balloon is inflated, plaque is pushed against the artery
walls. This causes the artery to widen, restoring blood flow. A stent, a tiny
mesh tube that looks like a small spring, is now used in most angioplasties.
Some stents are coated with medicine to help prevent the artery from closing
again.
Other Types of Treatment
Cell and gene therapies are currently being
researched, but are not yet available outside of clinical trials. For further
information about clinical trials, see the Links to
Other Information About Peripheral Arterial Disease section.
How Can Peripheral Arterial Disease Be Prevented?
There are a number of ways to try to prevent
peripheral arterial disease (PAD). If you are a smoker,
quit smoking. On average, smokers who develop PAD experience
symptoms 10 years earlier than nonsmokers who develop PAD. Work to control your
blood
pressure,
cholesterol,
and glucose levels. Talk with your doctor about beginning a supervised exercise
therapy program. If you are overweight or obese, work with your doctor to
develop a reasonable weight-loss plan. Finally, follow a low-fat,
low-cholesterol diet and eat more fruits and vegetables.
Living With Peripheral Arterial Disease
Ongoing Health Care Needs
Peripheral arterial disease (PAD) can be treated and
controlled.
If you are experiencing pain in calf or thigh
muscles after walking (intermittent claudication), try to take a break and
allow the pain to ease before walking again. Over time, this should increase
the distance that you can walk without pain.
Check your feet and toes regularly for sores or any
possible infection. Wear comfortable shoes that fit well. Maintain good foot
hygiene and have professional medical treatment for corns, bunions, or
calluses.
Be sure to keep your
blood
pressure,
cholesterol,
and blood sugar (if
diabetic) within normal ranges. Continue to carefully check
your feet daily for any sores or infections.
Treatment should decrease pain when walking and
allow you to walk longer distances without discomfort. There should be less
painful cramping of leg muscles. There may be improvement in the skin's
appearance and improvement in ulcers on your legs and feet.
Support Groups
The
Peripheral Arterial Disease Coalition is an alliance of
leading health organizations, vascular health professional organizations, and
Government agencies that have united to raise public and health professional
awareness about lower extremity PAD. The coalitions Patient Education
Workgroup is developing patient education tools.
The
Amputee Coalition of America and
National Limb Loss Information Center provide support for
people with limb loss.
Long-Term Care
For severe cases of chronic clinical limb ischemia
(CLI), a patient may be bed-bound and need total supportive care. CLI is a
severe blockage of the arteries that seriously decreases blood flow to the
hands, legs, and feet. People with severe CLI may experience burning pain in
the affected limb, and they can suffer from wounds that do not heal or from
tissue death (gangrene).
Key Points
- Peripheral arterial disease (PAD) occurs when a
fatty material called plaque builds up on the inside walls of the arteries that
carry blood to the limbs.
- PAD is a common, yet serious disease.
- PAD affects 8 to 12 million people in the United
States. An estimated 5 percent of U.S. adults over age 50 have PAD. Among
adults age 65 and older, 12 to 20 percent may have PAD.
- PAD can impair physical health and diminish a
person's ability to walk.
- People with PAD have an increased risk for heart
attack.
- Early diagnosis and treatment of PAD are
important to prevent disability and save lives.
- PAD screening for individuals at high risk is
very important.
- PAD can be treated with lifestyle changes,
medicines, and/or surgery and special procedures.
- Treatment often includes making long-lasting
lifestyle changes, including
quitting smoking,
lowering
high blood pressure,
lowering
high cholesterol levels, and lowering blood glucose levels if you are
diabetic.
- PAD treatment may stop the disease from
progressing and reduce the risk of heart attack, heart disease,
stroke, and kidney failure.
- Surgery may be necessary to supply more blood
flow to the leg if a person has severe symptoms.
Links to Other Information About Peripheral
Arterial Disease
NHLBI Resources
Non-NHLBI Resources
Clinical Trials
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