Atherosclerosis is a disease of the arteries which causes the formation of plaques in the walls of the arteries. Atherosclerotic plaques consist of deposits of fat, cholesterol, calcium, and large cells called macrophages.
These plaques can cause several problems. First, plaques can protrude into the artery, 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 needing emergency treatment.
Atherosclerosis commonly affects several key areas:
- The coronary arteries, leading to angina and myocardial infarction (heart attack)
- the cerebrovascular circulation, leading to stroke
- the renal arteries, leading to kidney disease
- the aorta, leading to aortic aneurysm
- and the blood vessels of the arms and (especially) the legs.
