Most symptomatic disease is due to atheromatous plaque formation, with subsequent stenosis, occlusion or embolisation of the vessel. Haemorrhage into an atheromatous plaque may precipitate a sudden vessel occlusion.
Atheroma tends to develop in the abdominal aorta and at the origins of major branches.
Intermittent claudication Ischaemia of the lower limbs is usually accompanied by effort- related cramp in the calves, thighs and buttocks, which disappears with rest. The site of claudication indicates the probable site of stenosis or occlusion - the higher the claudication the higher the atheroma is likely to be found. The walking distance on the flat is usually remarkably repeatable. Claudication is often accompanied by profound weakness as well as cramp in the affected muscles which have become acidotic from anaerobic exercise. More severe ischaemia produces a continuous pain at rest, particularly in bed.