Organ or part of body involved: Blood and arteries.

Symptoms and indications: Hyperlipidemia causes no symptoms until the atherosclerotic plaque obstructs blood flow. There are two mechanisms by which obstruction of blood flow through a vessel can occur. The first is progressive obstruction, called stenosis. A coronary stenosis causes angina Obstruction of blood vessels in the leg causes muscle pain with walking. The second mechanism by which blood flow can be obstructed is called plaque rupture. In this case, the plaque in the blood vessel wall breaks through the inner lining of the blood vessel, very much like the rupture of a pimple on the skin. When this occurs, a blood clot forms at the site of plaque rupture. A clot forming in a coronary artery causes a heart attack; one in the blood vessels of the brain causes a stroke. A rare condition is familial hypercholesterolemia. This condition, which occurs in one of every 500 people, can cause deposition of cholesterol in tendons, on the eyelids and in the cornea of the eye as well as the coronary arteries.

Causes and risk factors: More commonly, hyperlipemia is associated with a combination of factors, such as a mild inherited tendency, cigarette smoking, alcohol abuse, a diet containing excessive amounts of animal fats, lack of physical exercise, and obesity.

Prevention: A low-fat diet, regular exercise, and elimination of alcohol and smoking, and addition of antioxidants to the diet are recommended. Also, avoiding foods high in sugar, using monosaturated oils such as olive oil, and limiting salt intake to six grams a day.