Cholesterol is a soft, waxy substance present in all parts of the body including the nervous system, skin, muscles, liver, intestines, and heart. It is both made by the body and obtained from animal products in the diet. Cholesterol is manufactured in the liver for normal body functions including the production of hormones, bile acid, and vitamin D. It is transported in the blood to be used by all parts of the body.

In the blood stream, cholesterol combines with fatty acids to form high-density (HDL) and low-density (LDL) lipoproteins. LDLs are considered the "bad cholesterol," since they can stick together to form plaque deposits on the walls of your blood vessels, leading to atherosclerosis.