What is high cholesterol?

Cholesterol is a waxy, fat-like substance present in all cells and in the blood. Cholesterol is carried through the blood on lipoproteins (e.g., low-density lipoprotein (LDL) and high-density lipoprotein (HDL)). High amounts of LDL particles cause plaque (i.e., fatty deposits) to build up in the arteries.^[1] Plaque hardens and narrows arteries, which restricts blood flow to areas of the body like the heart or brain and can cause a heart attack or stroke.