If you have sudden or severe symptoms, call 999 or attend A&E. Do not use this website to decide whether to delay urgent care.
What is peripheral arterial disease?
Peripheral arterial disease (PAD) is a condition in which the arteries that carry blood to the legs become narrowed or blocked. The narrowing is almost always caused by atherosclerosis: a gradual build-up of fatty deposits, called plaque, inside the artery wall. Over time this narrows the channel through which blood flows, reducing the supply of oxygen and nutrients to the muscles and tissues of the leg.
PAD is very common. Studies consistently show that approximately 1 in 5 people over the age of 60 have some degree of peripheral arterial disease. Many of them have no symptoms at all. When symptoms do develop, the most common is a cramping pain in the leg when walking that clears with rest, known as intermittent claudication.
PAD matters beyond the leg. It is a marker of atherosclerosis throughout the body, including in the arteries of the heart and brain. People diagnosed with PAD have a significantly raised risk of heart attack and stroke, which is why treatment addresses the whole cardiovascular system as well as the leg symptoms.
What causes PAD?
The underlying cause in almost all cases is atherosclerosis. The same risk factors that cause coronary artery disease and stroke also drive PAD. The most significant are:
- Smoking: by far the most powerful modifiable risk factor for PAD. Smokers are up to four times more likely to develop the condition than non-smokers
- Diabetes: damages the artery wall directly and accelerates plaque build-up, and is particularly associated with disease in the smaller vessels below the knee
- High blood pressure: places sustained mechanical stress on artery walls, promoting plaque formation
- High cholesterol: excess lipids in the blood are incorporated into arterial plaques
- Age: the risk rises sharply after 60 as cumulative damage accumulates over decades
- Family history: a first-degree relative with PAD, coronary disease or stroke increases your own risk
- Kidney disease: chronic kidney disease independently accelerates vascular disease
Diagram: how peripheral arterial disease develops
Diagram for illustration only. Not a clinical image.
⚠ Red flags: acute limb ischaemia
- A leg or foot that becomes suddenly cold and pale
- Sudden severe pain in the leg or foot
- New numbness or weakness in the limb
- Pain in the foot at rest, especially at night
- Non-healing wounds, ulcers or blackened tissue (gangrene)
A sudden loss of blood supply to the limb (acute limb ischaemia) is an emergency requiring treatment within hours. Call 999 or attend A&E immediately.
What are the symptoms?
Symptoms depend on how severely the blood flow is reduced and which arteries are affected.
No symptoms
Many people with PAD have no leg symptoms at all, despite significant arterial narrowing. PAD may be found incidentally during a health check or when investigating another problem.
Intermittent claudication
Cramping, aching or tight pain in the calf, thigh or buttock that comes on with walking and is completely relieved by a few minutes of rest. The distance walked before pain develops tends to be consistent.
Rest pain
Severe aching or burning pain in the foot or toes that occurs at night or when lying down. Hanging the leg over the side of the bed or sitting up often brings partial relief, as gravity helps blood reach the foot.
Tissue loss
Ulcers on the foot or toes that fail to heal, or blackening (gangrene) of the toes. This indicates the most severe form of PAD and requires urgent specialist assessment to save the limb.
Rest pain, non-healing ulcers and gangrene together define what is now called chronic limb-threatening ischaemia (CLTI). This represents a vascular emergency: without prompt treatment, the limb may not survive.
How is PAD diagnosed?
Diagnosis begins with a careful history and examination, including feeling the pulses in the groin, behind the knee, and at the ankle and foot. The key diagnostic test is the ankle-brachial pressure index (ABPI).
The ABPI is a simple, non-invasive measurement. Blood pressure cuffs and a Doppler probe (a small handheld ultrasound device) are used to measure blood pressure at the ankle and in the arm. The ankle pressure is divided by the arm pressure to produce the index. NICE guideline CG147 and ESC 2024 guidelines recommend the ABPI as the first-line diagnostic test:
- ABPI 0.9 to 1.3: normal
- ABPI below 0.9: confirms PAD
- ABPI below 0.5: suggests severe disease with significant risk to the limb
- ABPI above 1.3: may be falsely elevated due to calcified (hardened) arteries, which is common in diabetes and kidney disease. In these cases, toe pressures or specialist assessment are needed
A Doppler duplex ultrasound scan is the next step for most patients. This maps the arteries in the leg in detail, showing exactly where the narrowings or blockages are and how severe they are. It is painless and provides the information needed to plan treatment.
When intervention is being considered, CT angiography or MR angiography may be performed to produce a detailed road map of the arterial anatomy from the aorta to the foot. This guides the choice between keyhole (endovascular) treatment and open bypass surgery.
Treatment for intermittent claudication
For most people with claudication, the arteries are narrowed but not completely blocked, and the leg is not at risk. The priority is to improve walking distance, protect against heart attack and stroke, and slow the progression of disease.
Supervised exercise programme
NICE CG147 recommends a supervised exercise programme as the first treatment for intermittent claudication, before any consideration of procedures. Supervised exercise involves two to three sessions per week for a minimum of three months, during which patients walk to the point of pain and then push through it under supervision.
The evidence for this is strong. Supervised exercise consistently improves maximum walking distance by 50 to 150% in patients who complete a programme. It also improves cardiovascular fitness, reduces heart attack and stroke risk, and in many patients produces a better long-term outcome than angioplasty for claudication symptoms.
Unfortunately, access to supervised exercise programmes on the NHS remains patchy. A private physiotherapy referral or a structured self-directed programme can provide an alternative where NHS access is limited.
Risk factor modification and medication
Smoking cessation is the single most important intervention for anyone with PAD. Continued smoking dramatically accelerates disease progression and significantly increases the risk of limb loss. Support from a smoking cessation service considerably improves success rates.
Antiplatelet medication (usually clopidogrel 75 mg once daily, or aspirin if clopidogrel is unsuitable) reduces the risk of blood clots forming on top of plaques and lowers the risk of heart attack and stroke. NICE CG147 and the ESC 2024 guidelines recommend antiplatelet therapy for all patients with symptomatic PAD.
High-intensity statin therapy (usually atorvastatin 80 mg once daily) reduces the rate at which plaques grow and stabilises existing plaques, reducing the risk of arterial events. Blood pressure and diabetes should also be optimised with appropriate medication.
Angioplasty and stenting
If symptoms remain severe and significantly limit daily life despite a supervised exercise programme and optimal medical therapy, a keyhole procedure to open up the narrowed artery may be considered. This is called angioplasty.
Angioplasty is performed under local anaesthetic or sedation through a small puncture in the groin or arm. A thin wire is guided through the narrowed artery under X-ray guidance, and a small balloon is inflated to widen it. A metal mesh tube called a stent may be placed to keep the artery open.
Angioplasty works well for shorter, focal narrowings, particularly in the aorta, iliac arteries (in the pelvis) and the upper part of the femoral artery in the thigh. Results for longer blockages or disease below the knee are less durable. Most patients go home the same day or the following morning.
NICE CG147 recommends that bypass surgery for claudication should only be offered when angioplasty has been unsuccessful or is unsuitable, and when imaging has confirmed that surgery is appropriate.
Treatment for chronic limb-threatening ischaemia (CLTI)
CLTI is a different situation from claudication. The leg is at immediate risk. Treatment focuses on saving the limb, and the priority is restoring blood flow as quickly as possible.
NICE CG147 requires that all patients with CLTI are assessed by a vascular multidisciplinary team before treatment decisions are made. The NVR 2024 State of the Nation report recorded a median time from non-elective admission to revascularisation of 6 days for CLTI patients in England, with only 50% treated within 5 days, a figure that highlights the ongoing pressure on vascular services and one of the reasons prompt access to specialist assessment matters.
Endovascular revascularisation (angioplasty and stenting)
Angioplasty is usually the first approach tried for CLTI because of its lower risk compared to open surgery. In CLTI, the aim is to restore at least one artery carrying blood in a continuous line from the aorta to the foot. Even partial restoration of flow can allow ulcers to heal and rest pain to settle.
Advances in catheter technology and imaging have significantly expanded what can be achieved endovascularly, including opening up diseased arteries below the knee to restore flow directly to the foot in patients with diabetes or renal disease.
Bypass surgery
Bypass surgery involves creating a new channel for blood to flow around the blocked artery, using either a vein taken from elsewhere in the body (usually the long saphenous vein from the leg) or a synthetic graft. Bypass surgery can treat longer and more complex disease patterns that are not suitable for angioplasty, and produces more durable results for disease below the knee.
The BEST-CLI randomised trial (2022), the largest trial ever conducted in CLTI, enrolled 1,830 patients and found that surgical bypass produced significantly better outcomes than endovascular treatment in patients who had a good quality vein available for use as a conduit. For patients without a suitable vein, the two approaches produced similar results. This trial has significantly influenced how CLTI is managed in specialist centres.
Amputation
When revascularisation is not technically possible or has failed, and the limb cannot be saved, amputation may become necessary to control infection, relieve pain, and allow the patient to rehabilitate. This is a last resort and every effort is made to avoid it. Overall, approximately 1 to 2% of people with intermittent claudication will eventually require amputation, but the risk is much higher in those who progress to CLTI without treatment.
Amputation, when it is the right decision, can dramatically improve quality of life by eliminating intractable pain and infection. With good prosthetic and rehabilitation support, many patients regain significant mobility.
Why is PAD a warning sign for the heart and brain?
Atherosclerosis is a systemic disease. If the arteries in the leg are narrowed, the same process is very likely affecting arteries elsewhere in the body, including those supplying the heart (coronary arteries) and brain (carotid arteries).
People diagnosed with PAD have a risk of heart attack and stroke that is two to three times higher than age-matched individuals without PAD. This is the reason antiplatelet medication and statins are so important in the management of PAD: they are not primarily treating the leg, they are protecting the heart and brain.
A vascular assessment for PAD will typically include a review of cardiovascular risk factors, blood pressure in both arms, and an assessment of whether the carotid arteries need imaging. Treating PAD is treating the whole vascular system.
What to do next
If you have pain in your legs that comes on with walking and is relieved by rest, particularly in the calf or thigh, it is worth getting a formal assessment with an ABPI measurement. Many cases of PAD go undiagnosed for years because the symptoms are attributed to ageing or muscle pain.
Early assessment means early treatment of cardiovascular risk, which can significantly reduce the long-term risk of heart attack and stroke, regardless of whether any procedure is needed for the leg itself.
A private vascular consultation can provide rapid access to a full assessment including ABPI measurement, duplex ultrasound and a personalised management plan. No GP referral is required.
Sources and further reading
- NICE CG147. Peripheral arterial disease: diagnosis and management.
- ESC 2024 Guidelines for the management of peripheral arterial and aortic diseases.
- NHS. Peripheral arterial disease (PAD).