Atherosclerosis is the buildup of fat and other material inside the artery walls.

Atherosclerosis is a disease in which plaque (plak) builds up on the insides of the arteries. Arteries are blood vessels that carry oxygen-rich blood to the heart and other parts of the body. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens and narrows the arteries. The flow of oxygen-rich blood to the organs and other parts of the body is reduced. This can lead to serious problems, including heart attack, stroke, or even death.