Atherosclerosis is a condition in which fatty material is deposited along the walls of arteries. This fatty material thickens, hardens, and may eventually block the arteries.

Atherosclerosis is just one of several types of "arterio"-sclerosis, which is characterized by thickening and hardening of artery walls, but the two terms are often used to mean the same thing.

Atherosclerosis is a common disorder of the arteries. Fat, cholesterol and other substances accumulate in the walls of arteries and form "atheromas" or plaques.

Eventually, this fatty tissue can erode the wall of the artery, diminish its elasticity (stretchiness) and interfere with blood flow. Plaques can also rupture, causing debris to migrate downstream within an artery. This is a common cause of heart attack and stroke.

Clots can also form around the plaque deposits, further interfering with blood flow and posing added danger if they break off and travel to the heart, lungs, or brain. Many physicians now suspect that there is an immune system component to the problem (inflammation may help cause atherosclerosis).

When blood flow in the arteries to heart muscle becomes severely restricted, it leads to symptoms like chest pain.

Risk factors include smoking, diabetes, obesity, high blood cholesterol, a diet high in fats, and having a personal or family history of heart disease. Cerebrovascular disease, peripheral vascular disease, high blood pressure, and kidney disease involving dialysis are also disorders that may also be associated with atherosclerosis.