Depending on your results, your doctor may recommend testing more often. The best blood test to check cholesterol is a "lipoprotein profile," which is done after fasting for nine to 12 hours. A lipoprotein is a substance in the blood that carries cholesterol and other fats to the body's cells. The most important lipoproteins are low-density lipoprotein (LDL) and high-density lipoprotein (HDL).

Cholesterol checks that don't involve fasting aren't as accurate, but they can give you a general idea about your cholesterol levels. These checks can give you a total cholesterol level and the HDL level. If your total is 200 mg/dl or more, or if your HDL level is less than 40 mg/dl, you will need to get a lipoprotein profile.

Low-density lipoprotein is the main cholesterol carrier in the blood and the main source of cholesterol buildup in the body. An optimal LDL level is less than 100 mg/dl. Near optimal is 100 to 129 mg/dl. High LDL level is considered 160 mg/dl and above. Triglycerides are another form of fat in the blood; like LDL cholesterol, they raise the risk of heart disease. A high triglyceride level is 200 mg/dl or more; borderline high is 150 to 199 mg/dl.

Researchers think that high-density lipoprotein carries cholesterol away from the arteries, to the liver, where it then passes from the body. The higher HDL number you have, the better. An HDL level of less than 40 mg/dl is considered a major risk factor for heart disease. An HDL level of 60 mg/dl or more helps lower your risk for heart disease.

Saturated fats and cholesterol in your diet make your blood cholesterol go up. You can estimate the amount of cholesterol and fat in foods by reading the nutrition labels. The main culprit is saturated fat, which is found in animal fats, including fats in meats and whole-milk dairy products. Try to limit your daily intake of saturated fats to no more than 7 percent of your diet (the average American diet is 11 percent). Cholesterol in your food also matters. Try to limit your intake of cholesterol (found in egg yolks, meat, poultry, seafood, and whole-milk dairy products) to no more than 200 mg a day. Trans fats (found in commercially baked goods and margarine) also can raise blood cholesterol. Try to limit your consumption of these. If you're overweight, losing weight can help lower your levels of LDL cholesterol and triglycerides, as well as boosting your HDL cholesterol level. Adding soluble fiber to your diet also can help lower LDL levels

Not being physically active is a risk factor for heart disease. You should try to get at least 30 minutes of moderate physical activity on most—if not all—days. (If you haven't been active, check with your doctor before beginning any new exercise program.)

You can't do anything about your age or family history of heart disease, but you can quit smoking and take steps to control your blood pressure. As people age, their cholesterol levels rise. Women's LDL levels tend to rise after menopause. High blood cholesterol also can run in families. Other risk factors for heart disease include little or no physical activity and obesity.

Depending on your cholesterol levels and your risk factors for heart disease, you may only need "therapeutic lifestyle changes"—changing your diet, adding exercise, losing weight. If your risk is higher, you will need drug treatment, as well as lifestyle changes, to lower your cholesterol levels. Medications for lowering cholesterol include statins, bile acid sequestrants, nicotinic acid, and fibric acids. Your doctor will help determine which medication is right for you.