Overview
Peripheral artery disease (PAD) is narrowing of the arteries supplying blood to the legs (and sometimes arms), caused by atherosclerosis. It reduces blood flow to muscles and tissues, causing pain on walking (intermittent claudication). Severe PAD causes critical limb ischaemia and tissue death, threatening limb loss. PAD is also a powerful marker of systemic cardiovascular disease.
How common is it?
PAD affects approximately 20% of people over 65 in the UK, though many are asymptomatic. About 1 in 5 cases involves symptomatic claudication. It is more common in smokers and people with diabetes.
Causes and risk factors
PAD results from atherosclerosis — progressive build-up of cholesterol-laden plaques in arterial walls reducing lumen diameter and blood flow.
Common risk factors
- Smoking (single most powerful risk factor — smokers have 4-fold increased PAD risk)
- Type 2 diabetes
- Hypertension
- Hypercholesterolaemia
- Age (over 50)
- Male sex
- Chronic kidney disease
- South Asian ethnicity
- Thromboangiitis obliterans (Buerger disease) in young heavy smokers
Symptoms
- Intermittent claudication: cramping or aching pain in calf, thigh, or buttock triggered by a reproducible walking distance, relieved by rest within 10 minutes
- Rest pain (in more severe PAD): burning pain in foot at rest, especially at night, relieved by hanging foot down
- Critical limb ischaemia: rest pain plus ulceration or gangrene
- Cold, pale, or bluish feet
- Absent or reduced foot pulses
- Slow-healing wounds on feet or legs
When to see a doctor
See a GP for persistent calf pain on walking. Seek urgent vascular assessment for rest pain, new foot ulcers, or blackened toes. These indicate critical limb ischaemia, which without treatment will lead to amputation.
Diagnosis
Ankle-brachial pressure index (ABPI): normal 0.9 to 1.4; below 0.9 diagnoses PAD. Duplex ultrasound maps disease. CT or MR angiography delineates anatomy for revascularisation planning.
Treatments
Cardiovascular risk factor modification
Smoking cessation, antiplatelet therapy (aspirin or clopidogrel), high-dose statin (atorvastatin 80mg), and blood pressure control are essential for all PAD patients to reduce heart attack and stroke risk.
Supervised exercise therapy
Structured walking programme (walking to the point of claudication pain, resting, then continuing) 3 times weekly for 3 months improves walking distance by 100 to 200% in most patients. First-line treatment for claudication.
Angioplasty and stenting
Balloon dilatation and stent deployment in diseased segments for claudication not responding to exercise therapy, or for critical limb ischaemia. Particularly effective for iliac and short femoral lesions.
Bypass surgery
Femoro-popliteal or femoro-distal bypass for complex multilevel disease or critical limb ischaemia not amenable to angioplasty. Autologous vein grafts have best long-term patency.
Cilostazol
A phosphodiesterase-3 inhibitor that increases walking distance by 40 to 60% in intermittent claudication. Used as adjunct or when exercise therapy is not possible.
Self-care and lifestyle
- Stop smoking immediately — this is the single most important intervention and dramatically slows disease progression
- Walk through claudication pain each day to build collateral circulation
- Meticulous foot care: inspect feet daily, avoid going barefoot, treat calluses and nail problems promptly
- Control diabetes stringently to prevent wound complications
Prevention
Smoking cessation is the most powerful prevention. Cardiovascular risk factor control (cholesterol, blood pressure, diabetes) prevents progression. Foot care education in people with diabetes reduces critical limb ischaemia risk.