Plaque is a buildup of cholesterol, white blood cells, calcium,
and other substances in the walls of arteries. Over time, plaque narrows the
artery, and the artery hardens (atherosclerosis).
reduces blood flow to the heart muscle, which can cause angina symptoms, such as chest pain or pressure.
Plaque in the large artery in the neck (carotid artery stenosis) may reduce
blood flow to the brain.
Plaques are covered
with a fibrous cap, which may rupture if some trigger causes a surge in blood
pressure or causes the artery to constrict. A person may have a heart attack or stroke if
a plaque breaks open, creating a blood clot that completely blocks blood flow
through the artery.