How to Define Cholesterol Levels

Cholesterol is a type of fat molecule produced by living organisms. The liver produces cholesterol irrespective of the amount supplied by diet. Although high levels are associated with cardiovascular disease, all cholesterol is not bad. Blood cholesterol levels are defined by the type and amount of cholesterol present in a given amount of blood.

Cholesterol Levels

• Physicians check blood cholesterol levels to assess a patient's risk of heart attack or stroke. The test, called a lipid profile, reveals three different cholesterol levels including total cholesterol, HDL cholesterol and LDL cholesterol.

Total Cholesterol

• Carrier molecules, called lipoproteins, carry cholesterol throughout the body. Lipoproteins are characterized by their densities and are either high-density lipoproteins or low-density lipoproteins, also known as HDL and LDL, respectively. The collective amount of HDL and LDL cholesterol in the blood represents total cholesterol. The American Heart Association considers levels less than 200 milligrams per deciliter desirable.

Good Versus Bad

• HDL cholesterol, or "good" cholesterol, removes cholesterol from the blood and transports it to the liver for removal from the body. LDL, or "bad " cholesterol, contributes to artery-narrowing, plaque formation. According to the American Heart Association, HDL cholesterol levels above 60 milligrams per deciliter and LDL cholesterol levels less than 100 milligrams per deciliter are optimal levels.