High cholesterol, a well-known risk factor for heart disease and stroke, affects about 1 in every 3 American adults. LDL cholesterol is known as the "bad" type of cholesterol because it forms plaques in your arteries, which can restrict the flow of blood and ultimately result in heart disease. But another type of cholesterol - HDL cholesterol - protects your arteries from this fate by sticking to LDL cholesterol particles and taking them to the liver. The liver then breaks down the LDL cholesterol. For this reason, HDL is known as the "good" cholesterol.
Lipids are fatty, oily compounds that are found in your bloodstream and in your body's cells. Cholesterol and triglycerides are both made out of lipids.