Claudication is pain and/or cramping in the lower leg due to inadequate blood flow to the muscles. The pain usually causes the person to limp. The word “claudication” comes from the Latin “claudicare” meaning to limp. Claudication typically is felt while walking, and subsides with rest.
It is commonly referred to as “intermittent” claudication because it comes and goes with exertion and rest. In severe claudication, the pain is also felt at rest.
What causes claudication?
Several medical problems can cause claudication, but the most common is peripheral artery disease. Peripheral artery disease (PAD) is caused by atherosclerosis, which is a hardening of the arteries from accumulation of cholesterol plaques that form on the inner lining of the arteries.
This is especially common at branching points of the arteries in the legs. Blockage of the arteries from these plaques causes low blood flow to the muscles in the legs.
When walking or exercising the muscles in the legs require more blood flow to increase oxygen to the cells. Atherosclerotic plaques cause decreased blood flow and decreased oxygen.
The muscles of the legs can ache and burn as a result of inadequate oxygen. This is felt as cramping in the legs.
What are the symptoms of claudication?
Pain and cramping in the legs is the main symptom of claudication. Pain can be sharp or dull, aching or throbbing, or burning.
The severity of the peripheral artery disease, the location of the plaque, and the activity of the muscles determine the severity of symptoms and location of pain.
Calf pain is the most common location for leg cramps. This is because the atherosclerotic plaques often begin in the arteries farthest from the heart. If the blockage or plaque formation is farther up the leg, the pain from claudication may be felt in the thigh.
If the blockage is in the aorta (the main artery from the heart to the legs) then symptoms may include pain in the buttocks or groin or erectile dysfunction.
How is Claudication detected?
A blockage in the circulation can be detected by examining the pulses and blood pressure in the legs. A blockage will lead to loss of one or more pulses in the leg. The blood pressure in your feet is measures using a handheld ultrasound device called a continuous wave Doppler.
The blood pressure in the foot can be measured and compared with arm blood pressure (which is usually normal). This measurement is called the ABPI (ankle brachial pressure index) and is expressed as a ratio. The ABPI provides an objective measure of the lower limb circulation.
Sometimes an arteriogram may be performed. An arteriogram is an x-ray of the arteries performed by injecting contrast (dye) into the artery at groin level.
The contrast outlines the flow of blood in the arteries as well as any narrowings or blockages.
Why does claudication come and go?
The usually intermittent nature of the pain of claudication is due to a temporary inadequate supply of oxygen to the muscles of the leg.
The poor oxygen supply is a result of narrowing of the arteries that supply the leg with blood. This limits the supply of oxygen to the leg muscles and is especially noticeable when the oxygen requirement of these muscles rises with exercise or walking.
Claudication that comes and goes is often referred to as intermittent claudication.
Claudication is not usually limb threatening and it is not necessary to treat it if the symptoms are mild. Claudication often remains stable, with no deterioration in walking distance over long periods. Less than one in ten patients will notice any reduction in walking distance during their lifetime.
However if your symptoms worsen, there are treatments available which you can discuss with your vascular surgeon.
General measures to improve walking distance include stopping smoking, taking more exercise and making sure you are not overweight. Blood tests to rule out other causes of atherosclerosis are often done.
These will include a blood sugar test to exclude diabetes, thyroid and kidney function tests and a cholesterol test.
There are a number of drugs on the market which claim to improve walking distance. These are not used by vascular surgeons, as the evidence for their effectiveness is very limited.
There is evidence that taking Aspirin or Clopidogrel is generally good for people with circulation disorders (heart, brain and legs). Please consult either your G.P or vascular surgeon for more information.
Who typically is affected by claudication?
Intermittent claudication is more common in men than in women. The condition affects 1% to 2% of the population under 60 years of age, increasing in incidence with age, to affect over 18% of persons over 70 years of age, according to the American Academy of Family Physicians.
There are three approaches to treating the claudication itself:
Exercise has been shown to more than double walking distance. Some hospitals can offer an exercise programme with structured exercises. If this is not available, a brisk (the best you can do) walk three times a week lasting thirty minutes will normally noticeably improve walking distance over three to six months.
Angioplasty (stretching the artery where it is narrowed with a balloon) may help to improve walking distance for some people. Overall it is less effective in the longer term than simple exercise.
Angioplasty is usually limited to narrowings or short complete blockages (usually less than 10cm) in the artery.
Bypass surgery is usually reserved for longer blockages of the artery, when the symptoms are significantly worse. There may be very short distance claudication, pain at rest, ulceration of the skin in the foot, or even gangrene in the foot or toes.
Is treatment successful?
The simple exercise program is very successful at increasing the walking distance. It provides a long term solution for the majority of people, and most importantly it is safe.
Because surgery (and to a lesser extent angioplasty) is not always successful, it can normally only be justified when a limb is threatened.
There will usually be pain keeping you awake at night, or ulceration or gangrene of the foot or toes. Half of the bypasses performed will need some “maintenance” procedure to keep them going. This may be an X-ray procedure or might involve further surgery.
What is the risk of losing my leg?
Very few patients with intermittent claudication will ever be at risk of losing a leg through gangrene. It is the vascular surgeon’s job to prevent this outcome at all costs. If there is thought to be any risk to the limb a vascular surgeon will always act to save the leg if at all possible.
You can minimise the risk of progression of your symptoms by following the advice below. It is the simple measures which are the most effective. The vast majority of patients do not need x-ray or surgical procedures to treat their symptoms.
How can I help myself?
There are several things you can do which can help. The most important are to stop smoking and take regular exercise. If you are a smoker, you should make a determined effort to give up completely. Tobacco is particularly harmful to claudicants for two reasons:
- Smoking speeds up the hardening of the arteries, which is the cause of the trouble
- Cigarette smoke prevents development of the collateral vessels which get blood past the blockage.
The best way to give up is to choose a day when you are going to stop completely, rather than trying to cut down gradually.
If you do have trouble giving up, please ask your doctor who can give you advice on additional help, or put you in touch with a support group.
It is also important not to be overweight. The more weight the legs have to carry around, the more blood the muscles will need. If necessary, your doctor or dietician will give you advice about a weight reducing diet.