What is intermittent claudication?

What is Intermittent Claudication

Intermittent claudication is leg muscle pain, cramping, fatigue, or discomfort that occurs reproducibly with walking or exercise, is caused by inadequate arterial blood flow to meet metabolic demands during exertion, and reliably resolves within 10 minutes of rest. 1

Pathophysiology and Mechanism

Claudication results from exercise-induced ischemia in specific limb muscle groups due to atherosclerotic peripheral arterial disease (PAD). 1 The underlying mechanism is more complex than simple supply-demand mismatch from arterial stenosis—it involves skeletal muscle metabolic dysfunction, neurological effects, and inflammatory processes. 1

• Blood flow is sufficient at rest, so ischemic symptoms are absent when not exercising 1
• During exercise, increased muscular metabolic demand cannot be met by the stenotic arterial supply, resulting in muscle fatigue and pain 1
• The pathophysiology includes skeletal muscle metabolic abnormalities, neurological changes, and inflammatory effects beyond just flow limitation 1

Anatomic Correlation with Symptoms

The location of arterial stenosis determines the specific pattern of leg symptoms: 1

• Iliac artery disease produces hip, buttock, and thigh pain, as well as calf pain 1
• Femoral and popliteal artery disease typically causes calf pain 1
• Tibial artery disease may produce calf pain or, more rarely, foot pain and numbness 1

Classic Presentation

The hallmark feature is reproducibility—the discomfort occurs at a predictable walking distance and resolves consistently with rest. 1 Classic claudication is cramping, aching, or pain most commonly in the calves, though it can extend to thighs or buttocks depending on lesion location. 1

Distinguishing from Pseudoclaudication

Vascular claudication must be differentiated from "pseudoclaudication" caused by non-vascular conditions: 1

• Lumbar spinal stenosis (neurogenic claudication)—can cause typical intermittent claudication symptoms but has different relief patterns 1
• Venous disease—pain usually at rest, worsens in evening, often improves with muscle activity 1
• Hip or knee arthritis—pain with walking but does not disappear at rest 1
• Peripheral neuropathy—characterized by instability while walking, pain not relieved by rest 1
• Chronic compartment syndrome 1

The Edinburgh Claudication Questionnaire is a standardized screening tool with 80-90% sensitivity and >95% specificity for diagnosing intermittent claudication. 1

Epidemiologic Context

Most patients with PAD do not have classic claudication symptoms—they are either asymptomatic or have atypical leg pain. 1 In the Rotterdam Study, only 6.3% of patients with documented PAD (ABI <0.90) reported classic claudication symptoms. 1 This means claudication represents only a subset of the broader PAD population, though it remains the most typical symptomatic presentation. 1

Clinical Significance

Intermittent claudication is a marker of systemic atherosclerosis with significant cardiovascular risk—up to 40% of patients with claudication die or suffer stroke within 5 years. 2 The condition causes significant functional impairment, mobility loss, and decreased quality of life. 1, 2

Diagnostic Approach

All patients with suspected claudication should undergo ankle-brachial index (ABI) measurement. 1, 3 If the resting ABI is normal (0.91-1.30) but classic claudication symptoms are present, exercise ABI testing should be performed to confirm the diagnosis. 1, 3