Arteriosclerosis characterized by irregularly distributed lipid deposits in the intima of large and medium-sized arteries; such deposits provoke fibrosis and calcification. In lower animals, atherosclerosis of swine and fowl mostly resemble atherosclerosis of man. Syn: nodular sclerosis.

Atherosclerosis is a multistage process set in motion when cells lining the arteries are damaged as a result of high blood pressure, smoking, toxic substances in the environment, and other agents. Plaques develop when high density lipoproteins accumulate at the site of arterial damage and platelets act to form a fibrous cap over this fatty core. Deposits block, or eventually entirely shut off, blood flow. Because atherosclerosis greatly raises the risk of angina, stroke, or heart attack (the leading cause of death in the U.S.), a primary goal of American health officials since the 1970s has been to educate individuals concerning the dangers of cholesterol. Plaque buildups, particularly in the carotid arteries, can be spotted by arteriography and ultrasound. Balloon and laser angioplasty have proved effective at minimizing plaques and restoring blood flow. However, prevention appears to be the primary means of attacking atherosclerosis: through low-fat diets, regular vigorous exercise, control of high blood pressure or diabetes, and avoidance of tobacco. See free radicals, low-fat diets.