Cholesterol comes from two sources; it is both produced by the body and found in the foods we eat. A blood cholesterol test can tell you whether your cholesterol levels are normal. Your health care provider will determine whether you need to fast before your cholesterol test.
Nonfasting Cholesterol Test
The nonfasting cholesterol test uses blood drawn at any point in the day. You don't have to follow a required diet before the test. Diet affects the levels of low-density lipoprotein cholesterol and triglycerides, rendering them unusable in this test. With the nonfasting cholesterol test, only the values for total cholesterol and high-density lipoprotein cholesterol will be usable. Depending on these values, your health care provider might require you to return for a fasting cholesterol test.
Fasting Cholesterol Test
Fasting cholesterol tests, also called lipid panels or lipid profiles, provide values for total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides. Since LDL cholesterol and triglycerides are affected by diet, the fasting cholesterol test requires you to eat and drink nothing for 9 to 12 hours before the blood test. You can drink water but stay away from coffee, tea and other beverages. Fasting cholesterol tests are usually scheduled in the morning to accommodate the long period of time without food or drink.
Medications
Some medications may affect your blood cholesterol test. Therefore, your health care provider may tell you to stop taking them before your cholesterol test. Don't stop taking medications unless your health care provider advises you to.
Drugs that may increase total cholesterol measurements include adrenocorticotropic hormone, anabolic steroids, beta-adrenergic blocking agents, corticosteroids, birth control pills, phenytoin, sulfonamides, thiazide diuretics and Vitamin D.
Drugs that may decrease total cholesterol measurements include allopurinol, androgens, colchicine, colestipol, fibrates, MAO inhibitors, neomycin, niacin and statins.
Test Procedure
The health care provider or technician will draw a vial of blood, usually from your arm. She will clean your arm using antiseptic and apply a plastic band to your upper arm to fill the vein with blood. She will insert a needle into the vein to remove the blood and collect it in a vial. She will remove the plastic band, the vial will fill and she'll remove the needle from your vein. She will cover the puncture site and send the vial to a laboratory for testing.
Frequency
National Cholesterol Education Program guidelines state that individuals 20 or older should have their cholesterol checked every five years. Your physician may recommend more frequent testing if you have a high total cholesterol, you are a man over age 45 or a woman over age 50, your HDL cholesterol is low or you have other risk factors for heart disease and stroke. Normal values for total cholesterol are below 200 mg/dL, and for HDL cholesterol are 40 mg/dL or above.
