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Cholesterol test
Definition A total cholesterol test is a rough measure of all the cholesterol and triglycerides in your blood. Cholesterol is a soft, wax-like substance found in all parts of the body. Your body needs a little bit of cholesterol to work properly. But too much cholesterol can clog your arteries, and lead to heart disease. Some cholesterol is considered "good" and some is considered "bad." Different blood tests are needed to individually measure each type of cholesterol. See also: - HDL test ("good" cholesterol)
- LDL test ("bad" cholesterol)
- Lipid profile
- High blood cholesterol and triglycerides
Alternative Names Total cholesterol How the test is performed Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood. Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding. In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding. How to prepare for the test To get accurate results, you should not eat or drink anything for 9 to 12 hours before the test. You may drink water, but other beverages such as coffee, tea, or soda should be avoided. Your health care provider may tell you to stop taking drugs that can affect the test. Never stop taking any medicine without first talking to your doctor. Drugs that may increase total cholesterol measurements include: - ACTH
- Anabolic steroids
- Beta-adrenergic blocking agents
- Corticosteroids
- Epinephrine
- Birth control pills
- Phenytoin
- Sulfonamides
- Thiazide diuretics
- Vitamin D
Drugs that may decrease total cholesterol measurements include: - Allopurinol
- Androgens
- Captopril
- Chlorpropamide
- Colchicine
- Colestipol
- Erythromycin
- Fibrates
- Isoniazid
- MAO inhibitors
- Neomycin
- Niacin
- Nitrates
- Statins
How the test will feel When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing. Why the test is performed This test is often done to determine your risk for coronary artery disease. High blood cholesterol and triglycerides have been linked to heart attack and stroke. Experts recommend that you have a complete cholesterol and triglycerides analysis every 5 years starting at age 20. The total cholesterol test is usually done as part of a lipid profile, which also checks for LDL, HDL, and triglycerides. Additional conditions under which the test may be performed: - Arteriosclerosis of the extremities
- Familial dysbetalipoproteinemia
- Familial hypercholesterolemia
- Hypothyroidism; primary
- Hypothyroidism; secondary
- Type 1 or type 2 diabetes
- Primary biliary cirrhosis
Normal Values Total cholesterol is an important measure of both bad and good cholesterol. Other lab tests are done to measure specific amounts of good (HDL) and bad (LDL) cholesterol. A cholesterol breakdown including LDL and HDL is preferred. The total cholesterol values listed below are used to target therapy: - Desirable: Under 200 milligrams per deciliter (mg/dL)
- Borderline high: 200 to 239 mg/dL
- High risk: 240 mg/dL and higher
What abnormal results mean In general, a total cholesterol value over 200 mg/dL may mean you have a greater risk for heart disease. However, LDL levels are a better predictor of heart disease, and they determine how your high cholesterol should be treated. High total cholesterol levels may be caused by: - Biliary cirrhosis
- Familial hyperlipidemias
- High fat diet
- Hypothyroidism
- Nephrotic syndrome
- Uncontrolled diabetes
Low cholesterol levels may be caused by: - Hyperthyroidism
- Liver disease
- Malabsorption (inadequate absorption of nutrients from the intestinal tract)
- Malnutrition
- Pernicious anemia
- Sepsis
What the risks are Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others. Other risks, although rare, may include: - Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Special considerations Pregnancy is usually associated with high cholesterol. Removal of the ovaries may also increase cholesterol levels. References Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Executive Summary of The Third Report of The National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, And Treatment of High Blood Cholesterol In Adults (Adult Treatment Panel III). JAMA. 2001 May 16;285(19):2486-97. Review date: 6/13/2007 Reviewed By: Glenn Gandelman, MD, MPH, FACC, Assistant Clinical Professor of Medicine, New York Medical College, Valhalla, NY. Review provided by VeriMed Healthcare Network
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