Peripheral arterial disease

Overview

Peripheral arterial disease, often called PAD, is a long-term condition that affects the blood supply to the legs and causes pain in the legs. It is usually caused by arteries becoming narrowed or blocked, most often by fatty deposits building up in the artery walls, which is called atherosclerosis. The most typical sign is calf pain on walking that settles with rest, although some people have no symptoms. There is no cure, but lifestyle changes and medicine can help reduce the symptoms. The British Heart Foundation notes that PAD also puts people at risk of coronary heart disease and stroke.

Symptoms

What a clinician may find

• A weak or absent pulse in the leg or foot
• Hair loss on the legs
• Shiny skin
• Sores on the legs or feet that heal slowly

Complications

• Critical limb ischaemia, where pain can occur at rest or wake a person at night
• Coronary heart disease, heart attack and stroke
• Sudden or rapid worsening of the blood supply, which may need emergency treatment

Diagnosis

A GP who thinks a person might have PAD looks at the legs and asks about symptoms and family history. The GP may arrange tests, such as blood tests and the ankle brachial pressure index, which compares blood pressure at the ankle and arm. When treatment to restore blood flow is being considered, NICE recommends duplex ultrasound as the first imaging test.

Treatment

There is no cure for PAD, but lifestyle changes and medicine can help reduce the symptoms. Treatment includes exercise, with supervised exercise programmes recommended by NICE for people with intermittent claudication. Medicines such as low-dose aspirin or clopidogrel may be prescribed to reduce the risk of blood clots, and statins to lower cholesterol. Procedures to restore blood flow, such as angioplasty or bypass, are considered when symptoms are severe or have not responded to other treatment.

Prevention

Stopping smoking and managing diabetes are described as part of living with PAD. The British Heart Foundation describes managing risk factors such as smoking, diabetes and high blood pressure to lower the chance of heart attack and stroke, with medicines such as statins, antiplatelets and blood pressure drugs.

Key facts

What are the symptoms of peripheral arterial disease?

The NHS describes peripheral arterial disease, often shortened to PAD, as a long-term condition that affects the blood supply to the legs and causes pain in the legs. The main symptom is leg pain that comes on when walking and eases after a few minutes of rest. This is called intermittent claudication. The British Heart Foundation describes a gripping, cramping feeling in the calves. MedlinePlus also lists numbness or heaviness in the leg muscles during walking or climbing stairs. Other possible signs include hair loss on the legs, shiny or discoloured skin, weakness or numbness, toenails that grow slowly or break easily, and sores on the legs and feet that heal slowly. MedlinePlus says weak or absent pulses in the legs or feet can be found, and the skin may look pale or bluish. The NHS notes that some people with PAD have no symptoms. If the narrowing becomes severe, pain can be constant or worse at night, which doctors call critical limb ischaemia.

What causes it and who is at risk?

The NHS says PAD is usually caused by the arteries that supply blood to the legs becoming narrowed or blocked. The main cause is atherosclerosis, where fatty deposits build up in the artery walls and restrict blood flow to the legs. The British Heart Foundation describes the same process in the arteries of the heart as coronary heart disease, and says having PAD puts a person at risk of coronary heart disease and stroke. Less common causes include inflammatory blood vessel conditions such as vasculitis. Smoking is described as the most significant risk factor for PAD. Diabetes, high blood pressure, high cholesterol and older age also raise the risk, and the British Heart Foundation also lists obesity. A study partly funded by the British Heart Foundation found smoking and diabetes to be the two leading risk factors for PAD, while cholesterol remained the top risk factor for coronary heart disease.

How is peripheral arterial disease diagnosed?

The NHS says a GP who thinks a person might have PAD will look at the legs and ask about symptoms and family history. They may also arrange tests, such as blood tests and a test that measures blood pressure and blood flow in the arms and ankles. This is the ankle brachial pressure index, or ABPI. NICE describes it as the highest ankle pressure divided by the highest arm pressure in each leg. A hand-held Doppler test can show whether a pulse is present and whether blood is flowing to a limb, according to the British Heart Foundation. NICE advises that a normal or raised ABPI alone should not rule out PAD in people with diabetes, because hardening of the arteries can affect the result. When treatment to restore blood flow is being considered, NICE recommends duplex ultrasound as the first imaging test. Contrast-enhanced magnetic resonance angiography is the next step when more detail is needed, and CT angiography is an alternative when that is not suitable. MedlinePlus, a US source, says no screening test is recommended for people without symptoms.

How is it treated?

The NHS says there is no cure for PAD, so treatment aims to ease symptoms and lower the risk of further cardiovascular disease. What is used depends on how severe the symptoms are, and it combines exercise, medicines and sometimes surgery. Stopping smoking is central. NICE recommends that a supervised exercise programme is offered to people with intermittent claudication, and the NHS describes supervised exercise as a first step. Most people with PAD are prescribed an antiplatelet medicine such as low-dose aspirin or clopidogrel to reduce the risk of blood clots. Statins are used to lower cholesterol, and blood pressure medicines are used if needed. Revascularisation, meaning treatment to restore blood flow, is considered when symptoms are severe or have not responded to other treatment. The two main options are angioplasty, which widens a narrowed artery with a balloon, and bypass grafting, which routes blood around a blockage. The NHS says angioplasty is less invasive, while bypass results are generally longer-lasting. NICE says angioplasty for claudication is offered only when imaging confirms it is suitable, advice on changing risk factors has been given, and supervised exercise has not improved symptoms.

What are the complications and when should someone get help?

PAD is linked to coronary heart disease and stroke, so treatment also aims to lower the risk of these. The NHS says that if symptoms develop quickly or get suddenly worse, this could be a sign of a serious problem needing immediate treatment. The British Heart Foundation advises calling NHS 111 or 999 in that situation. NHS Scotland guidance lists sudden limb pain, a pale or cold limb, loss of pulse, numbness and weakness or paralysis as reasons to go to A&E or call 999 straight away. Symptoms that come on slowly are usually raised at a GP appointment, and the NHS advises seeking non-urgent advice if leg pain comes on when walking and eases with rest, if pain is constant or worse at night, or if sores do not heal. Both angioplasty and bypass surgery carry a risk of serious complications, and the NHS says this risk is similar for the two. NHLBI, a US institute, describes PAD as a lifelong condition and says a person sees a healthcare provider who specialises in vascular diseases regularly. Quitting smoking can reduce symptoms and the risk of complications, according to NHLBI.

Frequently asked questions