What is bad cholesterol?

Bad cholesterol is LDL cholesterol, according to WebMD. It is considered bad cholesterol because it easily sticks to the walls of blood vessels and can cause atherosclerosis, which leads to heart disease and an increased risk of heart attack.

High levels of LDL cholesterol can lead to plaque formation in the arteries, according to WebMD. This often begins as early as childhood or early adolescence. Eating a diet low in saturated fat and high in fiber helps some people lower their LDL cholesterol. Regular exercise and eating plant sterols, such as cholesterol lowering margarine, also helps in some cases.Some people need medication to lower their LDL to acceptable levels.