Cholesterol and triglycerides are fatty substances called lipids. Both are essential for proper body functioning, but elevated blood levels of these lipids increase the risk of coronary heart disease and heart attacks.

• Video: What men need to know about their cholesterol

• Congestive Heart Failure: It can be controlled
• Coronary Artery Disease: Are you at risk?
• Get more information on the heart in our Heart Center

According to current guidelines from the National Cholesterol Education Program, everyone who is 20 years of age or older should have a blood test called a lipid profile (sometimes called a lipoprotein profile) at least once every five years.

This test, which measures blood levels of total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides, should be performed at your doctor's office. You will probably be asked to fast for at least 12 hours before the test, since what you eat can affect levels of blood triglycerides.

If fasting isn't possible, then only the values for total cholesterol and HDL cholesterol are obtained. If you are considered at low risk for coronary heart disease and the test results confirm this assumption, no further testing may be required. Otherwise, your doctor may ask you to return for a fasting lipid profile.

Your doctor will use the test results--along with the presence of other coronary heart disease risk factors (such as age, family history of premature heart disease, cigarette smoking, blood pressure, and diabetes)--to estimate your risk. If your total cholesterol, LDL cholesterol, or triglyceride levels are elevated (or if your HDL level is too low), your doctor will determine the most effective risk reduction measures for you to take.

These could involve changes in your diet, increasing physical activity, quitting smoking, moderating alcohol intake, taking medication, or a combination of these measures.