Peripheral Arterial Disease
Atherosclerotic narrowing of the lower-limb arteries that limits blood flow to exercising, then resting, muscle in a dose-dependent way, producing intermittent claudication and, once supply can no longer meet resting demand, critical limb ischaemia with rest pain, ulceration and gangrene.
First principles
PAD is atherosclerosis applying a flow-limiting stenosis to a supply-demand relationship
Atherosclerotic plaque narrows the arterial lumen, fixing a ceiling on maximal blood flow. At rest, even a significantly narrowed artery can usually still supply resting muscle demand, so patients are asymptomatic. On exercise, demand rises but a stenosed artery cannot increase flow to match it, producing anaerobic metabolism and ischaemic pain: intermittent claudication, pain that predictably comes on at a reproducible walking distance and eases with rest, exactly as a fixed supply ceiling against rising demand would predict.
Educational content pending clinical review. Not medical advice.