Definition: Plaques are caused by atherosclerosis, and are deposits in the walls of arteries that consist of fat, cholesterol, calcium, and large cells called macrophages.
Plaques can cause several problems. First, plaques can protrude into the artery, eventually causing a partial or complete obstruction to blood flow. Second, plaques can suddenly rupture, causing a blood clot (thrombus) to form, leading to sudden occlusion of the artery. (This condition is called arterial thrombosis.) Third, plaques can weaken the wall of the artery causing a ballooning out of the artery to form what is called an aneurysm. The rupturing of an aneuyrsm often produces bleeding that requires emergency treatment.
Also Known As: atherosclerotic plaque, atheroma
