Believe it or not, cholesterol is necessary for life. Cholesterol is a soft, waxy, fat-like substance that forms cell membranes for all organs in the body. It is needed to make hormones and vitamin D and to aid in digestion. The blood test for cholesterol is not to make sure you have it, but to screen for "hypercholesterolemia". That's the medical term for having too much cholesterol in the blood, which is a risk for heart disease.
Why would I need this test?
The test can tell if you have too much cholesterol, which leads to atherosclerosis, the buildup of fatty plaque in the walls of arteries. Atherosclerosis in the arteries around the heart (coronary arteries) can cause a heart attack. But plaque buildup (and high cholesterol) goes on silently for years before symptoms appear. The only way to know if your cholesterol is elevated is to have the level checked. Everyone 20 and older should have cholesterol measured every five years. If your cholesterol is high or if you are taking medication to lower your cholesterol, you will need to have it checked more often.
How is this test performed?
A needle is inserted into a vein (usually inside of the arm) and blood is drawn and collected in a tube. The blood is then sent to a laboratory for analysis.
How can I prepare for this test?
The recommended test to assess heart disease risk is a complete lipid profile. This requires you to fast for nine to 12 hours before the test.
What does the test measure?
The complete lipid profile includes four measurements:
- Total cholesterol
- LDL (bad) cholesterol, which is the main source of cholesterol buildup and blockage in the arteries
- HDL (good) cholesterol, which helps keep cholesterol from building in the arteries
- Triglycerides, another form of fat in your blood
What do the numbers mean?
The American Heart Association uses the following standards when evaluating test results:
Total cholesterol in milligrams per deciliter of blood (mg/dL):
- Less than 200 is desirable
- 200 to 239 is borderline high
- 240 and above is high
LDL cholesterol level (mg/dL):
- Less than 100 is optimal
- 100 to 129 is near optimal/above optimal
- 130 to 159 is borderline high
- 160 to 189 is high
- 190 and above is very high
HDL cholesterol level (mg/dL)*:
- Less than 40 mg/dL is low in men and less than 50 mg/dL is low in women
- 60 mg/dL or more helps lower your risk for heart disease
*Higher HDL numbers are better
- 150 to 199 mg/dL is borderline
- 200 mg/dL or more is high
- 500 and above is very high
The American Heart Association now suggests that a triglyceride level below 100 mg/dL is optimal.
What might an undesirable result mean?
High levels may mean an increased risk of:
- Coronary heart disease
- Pancreatitis (inflammation of the pancreas)
Would a child need a cholesterol test?
Children can start to develop fatty deposits in their arteries at a very young age. There is mounting evidence that elevated cholesterol levels in children play a role in the development of adult heart disease. Because of this, the American Academy of Pediatrics recommends that children have a fasting lipid profile after 2 years of age if they have certain risk factors. These include a family history of high cholesterol or early heart disease. Other risks include being overweight or having high blood pressure or diabetes.
Ask your child's doctor about whether a cholesterol test is right for your child.
How is high cholesterol treated?
Elevated blood cholesterol is one of several conditions that can raise your risk of getting heart disease. If your cholesterol is high, your doctor will suggest some lifestyle changes.
Diet can have a direct impact on cholesterol levels. By sticking to a diet lower in saturated fat, you may be able to lower your cholesterol levels. If you are overweight, losing weight may also drop the levels. When lifestyle modifications fail to lower these levels to a desirable level, or when other risk factors for heart disease are also present, your doctor may also prescribe medication to lower your cholesterol levels.
Created on 08/01/2001
Updated on 12/07/2011
- Agency for Healthcare Research and Quality. Talk with your health care provider about high cholesterol.
- American Association for Clinical Chemistry. Cholesterol: the test.
- Miller M, Stone NJ, Ballantyne C, et. al. Triglycerides and Cardiovascular Disease. A Scientific Statement From the American Heart Association.
- National Heart Lung and Blood Institute. National cholesterol education program expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (Adult Treatment Panel III).