High blood cholesterol is a serious problem: it is a "risk factor" for heart disease. That means that having high blood cholesterol increases your chance, or risk, of getting heart disease. The higher your blood cholesterol, the greater your risk of getting heart disease. And heart disease is the number one killer of both men and women in the United States.

Two specific kinds of blood cholesterol are low density lipoproteins (LDL) and high density lipoproteins (HDL). LDL-cholesterol, sometimes called "bad" cholesterol, causes the cholesterol to build up in the walls of your arteries. Thus, the more LDL you have in your blood, the greater your heart disease risk. In contrast, HDL-cholesterol, sometimes called "good" cholesterol, helps your body get rid of the cholesterol in your blood. Thus, if your levels of HDL are low, your risk of heart disease increases.

Every adult, ages 20 and older, should have his or her blood cholesterol checked at least once every 5 years. Here's a quick look at the numbers and what they mean:

Cholesterol levels less than 200 mg/dL are considered desirable, while levels of 240 mg/dL or above are high and require more specific attention. Levels from 200-239 mg/dL also require attention especially if your HDL-cholesterol is low or if you have two or more other risk factors for heart disease. Look at the chart to see how many risk factors you have. Your doctor looks at all your risk factors to decide what you need to do to lower your blood cholesterol and reduce your risk of heart disease.

HDL-Cholesterol. Unlike total and LDL-cholesterol, the lower your HDL, the higher your risk for heart disease. An HDL level less than 35 mg/dL is considered low and increases your risk for heart disease. The higher your HDL, the better. An HDL level of 60 mg/dL or above is high.

LDL-Cholesterol. Your doctor will likely check your LDL-cholesterol level if your:

Your LDL level gives a better picture of your risk for heart disease than your total cholesterol. Here are the categories for LDL levels:

Lowering LDL is the main aim of treatment for a cholesterol problem. If your LDL level puts you at high-risk and you have fewer than two other risk factors for heart disease, then your treatment goal is an LDL level of less than 160 mg/dL. However, if you have two or more other risk factors for heart disease, your LDL goal should be less than 130 mg/dL. If you already have heart disease, your LDL should be even lower -- 100 mg/dL or less.

Your blood cholesterol levels are affected by:

• What you eat-
  The saturated fat and cholesterol in the food you eat raise total and LDL-cholesterol levels.

• Overweight-
  Being overweight can make your LDL-cholesterol level go up and your HDL level go down.

• Physical activity/exercise-
  Increased physical activity helps to lower LDL-cholesterol and raise HDL-cholesterol levels.

• Heredity-
  Your body makes all the cholesterol it needs, and your genes influence how your body makes and handles cholesterol.

• Age and gender-
  Blood cholesterol levels in both men and women begin to go up at about age 20. Women before menopause have levels that are lower than men of the same age. After menopause, a woman's LDL-cholesterol level goes up -- and so does her risk for heart disease.

If you already have heart disease, you have a great deal to gain by lowering your cholesterol level. If you lower your blood cholesterol, you can possibly prevent future heart attacks, and maybe even slow down or reverse some of the cholesterol buildup in the arteries. Remember, your LDL should be 100 mg/dL or less.