Intermittent Claudication

The symptoms of intermittent claudication vary from mild to severe. Pain may include:

• aching
• cramping
• numbness
• weakness
• heaviness
• fatigue

Your pain can be severe enough to limit how much you walk or exercise. If the cause is PAD, resting for 10 minutes relieves the pain. That’s because your resting muscles need less blood flow.

Intermittent claudication is a common early symptom of PAD. It’s caused by a blockage of the arteries that supply blood to your legs and elsewhere peripherally.

Over time, plaques accumulate on the walls of your arteries. The plaques are a combination of substances in your blood, such as fat, cholesterol, and calcium. These plaques narrow and damage your arteries, decreasing blood flow and decreasing the oxygen getting to your muscles.

Other possible causes of intermittent claudication (and other conditions that may cause symptoms that are similar to, but different from, intermittent claudication) can involve your muscles, bones, or nerves. Some examples are:

• lumbar spinal stenosis, which produces pressure on the nerves as the spaces within your spine narrow
• nerve root compression, such as from a herniated lumbar disk
• peripheral neuropathy associated with diabetes mellitus, which may occur alongside intermittent claudication caused by PAD
• arthritis in hip, knee, or ankle
• chronic exertional compartment syndrome, when pressure builds up in the leg muscles during exercise
• muscle strain
• Baker’s cyst
• changes in shoe heel height
• deep venous thrombosis, a blood clot deep in the vein
• endofibrosis of the external iliac artery, the artery that supplies blood to your legs
• fibromuscular dysplasia, a non-inflammatory blood vessel disease that causes abnormal growth in an artery wall
• vasculitides (conditions involving inflammation and death of blood vessels), including giant-cell arteritis, Takayasu’s arteritis, Buerger’s disease, polyarteritis nodosa, or Behçet’s disease

In younger people, other (rare) causes of intermittent claudication are:

• popliteal entrapment, or compression of the main artery behind the knee
• cyst formation in the main artery behind the knee
• persistent sciatic artery, which continues into the thigh

Your doctor will ask you about your symptoms and your medical history. They’ll want to know when your symptoms began, how long they last, and what seems to relieve them.

Specifically, they’ll want to know whether:

• you feel the pain in your muscle and not your bone or joint
• the pain always occurs after you walk a certain distance
• the pain goes away when you rest for 10 minutes or so

How far you can walk without pain may indicate the severity of PAD. If your pain doesn’t go away after resting, it may indicate a cause of intermittent claudication other than PAD. For example:

• Pain from spinal stenosis feels like weakness in your legs. It begins soon after you stand up. Pain may be relieved by leaning forward.
• Pain from irritation to a nerve root starts in the low back and radiates down your leg. Resting may or may not bring relief.
• Pain from hip arthritis is related to weight bearing and activity.
• Arthritic (inflammatory joint) pain may be continuous, with swelling, tenderness, and heat in the affected area. Pain is intensified with weight bearing.
• Pain from a Baker’s cyst may have swelling and tenderness behind your knee. It’s aggravated by activity, but not relieved by resting.

Risk factors for PAD

The doctor will also review your potential risk factors for PAD, including:

• tobacco smoking (this is the strongest risk factor)
• increasing age (some studies show a twofold increase in risk for every 10-year increase in age)
• diabetes mellitus
• high blood pressure
• high lipids (cholesterol and triglycerides)
• decreased kidney function
• race (PAD rates for African-Americans are about twice those of non-African-Americans)

Weaker risk factors for PAD include obesity, elevated homocysteine, elevated C-reactive protein and fibrinogen, and genetic factors.

Diagnostic tests

The doctor will physically examine you and may use some tests to confirm intermittent claudication and PAD or indicate other conditions. If you’re a candidate for surgery, the doctor will likely order a variety of imaging tests.

The most important screening test for PAD/intermittent claudication is the ankle-brachial index (ABI). This test uses ultrasound imaging to measure and compare your arterial blood pressures at your ankle and arm. The ratio of ankle systolic pressure to arm (brachial) systolic pressure indicates the severity of PAD:

• ABI of greater than 1.0–1.4 is considered normal.
• ABI of 0.9–1.0 is acceptable.
• ABI of 0.8–0.9 is considered mild PAD.
• ABI of 0.5–0.8 is considered moderate PAD.
• ABI of less than 0.5 is considered severe PAD.

The ankle-brachial index may be sufficient to diagnose PAD as the cause of your intermittent claudication.

Another noninvasive test is used to determine if the intermittent claudication may be caused by a lumber spinal problem. This looks at your gait (how you walk). If you have a spinal nerve problem, the angle of your ankle and knee may be different than if you have PAD.

Among the physical symptoms/signs of PAD in your legs are:

• cool skin
• wounds that don’t heal
• burning or aching in your feet while you’re resting
• shiny skin and absence of hair
• pale skin when your leg is elevated
• rushing sounds (bruits) in your leg arteries
• abnormal capillary refill time, the length of time it takes for blood refill, after pressure is applied to your skin for a few seconds.

In extreme cases, the disease is so advanced that the leg may have chronic pain while resting, or tissue loss or gangrene. An estimated 1 percent of those with PAD have these symptoms.

Treatment for intermittent claudication will depend on the underlying cause.

PAD

If your intermittent claudication is caused by PAD, a first step is to modify your risk factors:

• Stop smoking tobacco products.
• Reduce and control high blood pressure.
• Reduce and control high lipids.
• Begin a supervised exercise program.
• Eat a balanced, healthy diet (a low-carbohydrate diet has proven helpful in diabetes control and weight loss).

A main aim of treatment is to reduce the risk of heart attack, which is associated with PAD.

Your doctor may prescribe drugs to help with lowering blood pressure and lipids. They also may prescribe drugs to improve blood flow to your legs. Antiplatelet drugs have been shown to reduce the risk of heart problems associated with atherosclerosis and PAD, although they don’t improve claudication.

Other possible treatments include the following:

• Vascular bypass surgery may be used to revascularize leg arteries.
• Percutaneous transluminal peripheral arterial angioplasty is a minimally invasive procedure to unblock peripheral arteries.
• Angioplasty may involve placement of a stent to help keep the peripheral artery open or an atherectomy.

A 2015 review of PAD treatment studies noted that these surgeries/procedures improve blood flow, but the effects may not last, and they may be associated with higher death rates. Each individual is different. Discuss the pros and cons of surgery with your doctor.

Other causes

Treatment for other causes of intermittent claudication includes leg rest, over-the-counter or prescription painkillers, physical therapy, and, in some cases, surgery.

The recommended exercise for intermittent claudication is walking. A meta-analysis from 2000 recommended:

• Walk 30 minutes at least three times a week for the most benefit.
• Rest when near your highest pain point.
• Follow the program for at least six months.
• Walk in a supervised program for best results.

The results showed an average 122 percent increase in the distance people were able to walk.

A 2015 study found significant improvement after three months among those who participated in a supervised walking and educational program.

Home exercise programs may include other leg exercises or walking on a treadmill. Several studies note that that these programs may be more convenient, but that supervised exercise is more beneficial. One review found that the results of a supervised program of exercise were equivalent to angioplasty in terms of walking improvement and quality of life.

The outlook for intermittent claudication depends on the underlying disease. Baker’s cysts can be treated and usually cured. Other muscular and nerve diseases can also be treated to provide significant pain and symptom improvement.

If PAD is the cause of intermittent claudication, it’s treatable but not curable. Physical therapy can improve walking distance. Drugs and surgery can treat PAD and minimize its risk factors. Aggressive treatment to minimize risk factors is advised.

Most important is treatment for any cardiovascular disease. In an article written in 2001, as many as 90 percent of people with intermittent claudication were found to have cardiovascular disease. People with intermittent claudication have a much higher mortality risk than others of their age who do not.

The 5-year mortality rate for intermittent claudication from all causes is 30 percent, according to a 2001 clinical review. Of those deaths, an estimated 70 to 80 percent can be attributed to cardiovascular disease. A more recent study (2017) found improvements in the mortality rate at 5 years.

There’s ongoing research to find better treatments, including gene therapy and methods for increasing new blood vessel growth (therapeutic angiogenesis). Talk to your doctor about current therapies, as well as new therapies and clinical trials.