Well, your body needs cholesterol to build and maintain cell membranes; the membranes need it to produce hormones, vitamin D and bile acids. The bile acids actually help to digest fat. Most cholesterol is made by your body itself. There is, however, bad and good cholesterol. Your body only needs a little good cholesterol in order to be able to function well. When your cholesterol is high, it means you have too much bad cholesterol.

High Density Lipoprotein

Cholesterol is manufactured in the liver. Foods from animals also contain cholesterol - probably because animals have livers, too. Some vegetables can also contain cholesterol and saturated fat. Cholesterol is a fat-like substance that bonds to a protein before beginning its travel through the bloodstream. When cholesterol bonds to a protein the result is a lipoprotein.

The test you take to measure cholesterol actually measures lipoproteins. These lipoproteins are sorted by their density - the measure of fat versus protein in the combination. High density means that there is more protein compared to fat. High density lipoproteins (HDL) are your good cholesterol. They do the necessary work assigned to cholesterol, don't clog up your arteries and help flush excess fat from your body.

Low density lipoproteins (LDL), very low density lipoproteins (VLDL) and triglycerides (a type of fat carried by LDL and VLDL) make up the bad cholesterol that cause plaque buildup on artery walls and predict heart disease. Why do levels of bad and good cholesterol vary from person to person? Factors that affect cholesterol levels include being overweight, a diet with too much saturated fat and cholesterol, not enough exercise, heredity and certain medical conditions or medicines. Cholesterol tends to increase with age, too.

If your cholesterol is too high, your doctor will help you find out the likely causes. In general, you can always increase good cholesterol and decrease bad cholesterol by watching your diet, exercising regularly and losing weight - in other words, by following a healthy lifestyle. You'll need your doctor's help with the other factors. Don't worry about having too little cholesterol. That's not likely to happen. Concentrate on having enough good cholesterol, less bad cholesterol and the rest will take care of itself.