How Are Cholesterol Tests Done?

The American Heart Association recommends cholesterol testing every five years for adults over the age of 20. The test requires a blood sample and uses information stored in proteins to measure your cholesterol levels.

Cholesterol

• The cholesterol steroid performs many important functions in your body. Cell membranes form from cholesterol, as well as bile acids and hormones. Your system requires cholesterol in a certain amount, though too much cholesterol collected from fattening foods and other sources can damage your system and increase the risk for some cardiac diseases.

Blood Content

• Lipoproteins circulate in your blood and collect excess cholesterol for later disposal. Because the cholesterol stays inside these proteins, a blood test can measure the amount of cholesterol in your blood, and extrapolate to estimate the cholesterol levels of your body.

Procedure

• Most commonly, a physician or nurse will draw blood from your arm. Since the test only requires a small amount of blood, the tester will occasionally prick your finger for a sample, or use a fingerstick. The blood sample travels to a laboratory for thorough testing.

Analysis

• The laboratory will report your cholesterol levels as milligrams of cholesterol per deciliter of blood, usually in the "mg/dl" format. The American Heart Association labels results under 200 as desirable, and results higher than 240 as high-risk. Your physician considers the number alongside other factors such as heredity, lifestyle and genetics before making any treatment recommendations.

Test Requirements

• Cholesterol tests often accompany lipid profile tests, which require fasting for a number of hours before the test. Ingesting anything other than water in the prescribed pretesting period may skew the results of the test and require you to return for a repeat of the procedure. If taken without a lipid profile test, a cholesterol test requires no fasting.