Claudication

Claudication describes reproducible muscle pain triggered by activity and relieved within minutes of rest. It is a symptom of peripheral artery disease (PAD) — narrowing of the arteries supplying blood to the limbs, most often the legs.

**Pathophysiology**

The peripheral arteries deliver oxygenated blood to the muscles of the arms and legs. At rest, even significantly narrowed arteries can usually supply enough blood to meet basal metabolic demand. During exercise, however, active muscles need a substantial increase in blood flow. When atherosclerotic plaques limit arterial diameter, this demand cannot be met — muscles become oxygen-deprived, producing the characteristic cramping or aching that forces the patient to stop.

Atherosclerosis — the accumulation of cholesterol, inflammatory cells, and fibrous tissue in arterial walls as plaques — is the underlying cause in the vast majority of cases. As plaques enlarge they narrow and stiffen the artery; ruptured plaques trigger clot formation, causing acute-on-chronic worsening.

**Claudication as a cardiovascular warning sign**

Claudication is not merely a local limb problem. It reflects systemic atherosclerosis — patients with symptomatic PAD have a two- to three-fold increased risk of myocardial infarction and stroke. Identifying and aggressively managing cardiovascular risk factors is as important as treating the limb symptoms.

**Risk factors**

- Smoking (the strongest modifiable risk factor) - Diabetes mellitus - Hypertension - Hypercholesterolaemia - Obesity (BMI > 30) - Chronic kidney disease - Age over 70, or over 50 with smoking or diabetes - Family history of atherosclerosis, PAD, or claudication

**Complications of untreated or progressive PAD**

- Non-healing skin ulcers - Gangrene (tissue death from ischaemia) - Limb amputation - Myocardial infarction and stroke (from shared atherosclerotic disease)

**Management**

*Exercise therapy:* Structured supervised exercise — walking to moderate pain, resting to recovery, and repeating for 30–45 minutes, three or more times per week — is the most effective non-invasive treatment. It improves walking distance, collateral circulation, and cardiovascular fitness.

*Cardiovascular risk reduction:* Smoking cessation, antiplatelet therapy (aspirin or clopidogrel), statin therapy, blood pressure control, and glucose management address the underlying disease and reduce cardiac and cerebrovascular event risk.

*Pharmacological:* Cilostazol, a phosphodiesterase inhibitor with vasodilatory properties, modestly increases pain-free walking distance.

*Neuromodulatory:* Spinal cord stimulation significantly improves rest pain, tissue perfusion, and quality of life in patients with severe limb ischaemia who are not candidates for vascular reconstruction.

*Vascular intervention:* Percutaneous transluminal angioplasty (with or without stenting) or surgical bypass restores blood flow for patients with lifestyle-limiting claudication unresponsive to exercise and medical therapy.