Peripheral arterial disease

Symptoms

Many people with PAD have no symptoms. However, some develop a painful ache in their legs when they walk, which usually disappears after a few minutes' rest. The medical term for this is "intermittent claudication".

The pain can range from mild to severe, and usually goes away after a few minutes when you rest your legs.

Both legs are often affected at the same time, although the pain may be worse in 1 leg.

Other symptoms of PAD can include:

• hair loss on your legs and feet
• numbness or weakness in the legs
• brittle, slow-growing toenails
• ulcers (open sores) on your feet and legs, which do not heal
• changing skin colour on your legs, such as turning paler than usual or blue – this may be harder to see on brown and black skin
• shiny skin
• in men, erectile dysfunction
• the muscles in your legs shrinking (wasting)

The symptoms of PAD often develop slowly, over time. If your symptoms develop quickly, or get suddenly worse, it could be a sign of a serious problem requiring immediate treatment.

Causes

PAD is a form of cardiovascular disease (CVD) because it affects the blood vessels.

It's usually caused by a build-up of fatty deposits in the walls of the leg arteries. The fatty deposits (atheroma) are made up of cholesterol and other waste substances.

The build-up of fatty deposits on the walls of the arteries makes the arteries narrower and restricts blood flow to the legs. This process is called atherosclerosis.

There are certain things that can increase your chances of developing PAD and other forms of CVD, including:

• smoking – the most significant risk factor
• type 1 diabetes and type 2 diabetes
• high blood pressure (hypertension)
• high cholesterol
• growing older

Diagnosis

If the GP suspects peripheral arterial disease (PAD), they'll first carry out a physical examination of your legs.

The GP will look for symptoms such as:

• shiny skin
• brittle toenails
• hair loss on your legs and feet
• the pulse in your leg being very weak or undetectable
• leg ulcers

The GP may also ask about your personal and family medical histories.

The ankle brachial pressure index

The ankle brachial pressure index (ABPI) test is widely used to diagnose PAD, as well as assess how well you're responding to treatment.

You may have an ABPI test at your local surgery or you may be referred to your local podiatry service.

Podiatrists are feet specialists, but many have also been trained to carry out an ABPI test.

• while you lie on your back, the blood pressure in your upper arms and ankles will be measured using a cuff and a Doppler probe. A Doppler probe uses sound waves to determine the blood flow in your arteries
• after your scan, your blood pressure's second results (from your ankles) will be divided by the first results (from your arms)

If your circulation is healthy, the blood pressure in both parts of your body should be exactly or almost the same. This would make the result of your ABPI 1.

However, if you have PAD, the blood pressure in your ankle will be lower because of a reduction in blood supply. This would make the result of the ABPI less than 1.

In some cases, ABPI may be carried out after you run on a treadmill or cycle on an exercise bike. This is to see the effect of physical activity on your circulation.

This is usually carried out in hospital.

Further testing

In most cases, the GP will be able to confirm a diagnosis of PAD by doing a physical examination, asking about your symptoms and checking your ABPI score.

Further testing is usually only required if:

• there's uncertainty about the diagnosis. For example, if you have leg pain but your ABPI score is normal
• you do not fit the expected profile of somebody with PAD – for example, you are younger than 60 and have never smoked
• the restriction of blood supply in your leg is severe enough that treatment, such as surgery, may be required

Additional hospital-based tests that may be carried out include:

• an ultrasound scan – where sound waves are used to build up a picture of arteries in your leg. This can identify where in your arteries there are blockages or narrowed areas
• an angiogram – where a liquid called a contrast agent is injected into a vein in your arm. The agent shows up clearly on a CT scan or MRI scan and produces a detailed image of your arteries

Treatment Options

PAD is largely treated through lifestyle changes and medication.

Exercising regularly and not smoking are the main lifestyle changes that can ease the symptoms of PAD and reduce the chances of it getting worse. It's also important to:

• eat a healthy diet
• lose weight, if you're overweight or obese
• moderate your consumption of alcohol

The underlying causes should also be treated, including high blood pressure, high cholesterol and diabetes. Medicine and, in some cases, surgery can be used to improve the blood flow in your legs.

With treatment, most people's symptoms remain stable and some people may experience an improvement in their pain.

If treatment is unsuccessful, there's a risk of potentially serious complications.

Complications

PAD is not immediately life-threatening, but the process of atherosclerosis that causes it can lead to serious and potentially fatal problems.

Coronary heart disease (CHD)

The blockages in the arteries in the legs can also affect other areas of your body, such as the arteries supplying the heart and brain. 

This means that having PAD makes you more likely to develop another form of cardiovascular disease (CVD), such as:

• coronary heart disease
• stroke
• heart attack
• angina

Critical limb ischaemia (CLI)

If the blood flow to the legs becomes severely restricted, critical limb ischaemia (CLI) can develop. CLI is an extremely serious complication that can be challenging to treat.

Symptoms of CLI include:

• a severe burning pain in your legs and feet that continues even when you're resting
• your skin turning pale, shiny, smooth and dry
• wounds and ulcers (open sores) on your feet and legs that do not heal
• loss of muscle mass in your legs
• the skin on your toes or lower limbs becoming cold and numb, turning red and then black, and/or beginning to swell and produce smelly pus, causing severe pain (gangrene) – changes in skin colour may be harder to see on brown and black skin

When To See A Doctor

You should see a GP if you experience recurring leg pain when exercising.

Many people mistakenly think this is just part of growing older, but there's no reason why an otherwise healthy person should experience leg pain.