Cholesterol

Synonyms

Fats; Lipids

Definition

Cholesterol is a naturally occurring lipid found in the bloodstream and in cells throughout the body. It is an important component of cell membranes and some hormones. However, hypercholesterolemia, or high blood concentrations of cholesterol, is a major risk factor for heart disease and stroke.

Current Knowledge

Cholesterol does not typically exist on its own in the blood; it is transported to and from cells by lipoprotein molecules. Low-density lipoprotein (LDL) is the major carrier of cholesterol. In the presence of high circulating concentrations, LDL-cholesterol gradually builds up in and on the walls of the coronary, cerebrovascular, or peripheral arteries. Together with coagulation factors and platelets, cholesterol deposits on the vessel walls can form thick hard “plaques” which, over time, can occlude the blood vessels in a process called “atherosclerosis.” Therefore, a high level of LDL-cholesterol (usually greater than 160 mg/dL) indicates an...