Cholesterol Tests

Your Care Explained > Tests and Procedures : Cholesterol Tests

Cholesterol testing is used to estimate the risk of developing heart disease and to monitor the effectiveness of cholesterol-lowering medications.

Recent studies indicate that a low HDL-C level might be more predictive of heart disease in women than a high LDL-C is.

What is a Cholesterol Test?

A blood test for total cholesterol measures the concentration of all types of cholesterol in the blood and can be performed any time without advance preparation. However, a serum lipid profile that measures not only the total cholesterol level in the blood, but also the concentrations of several types of fat molecules—LDL cholesterol, HDL cholesterol, and triglycerides—is necessary to accurately predict heart disease risk. It is done only after overnight fasting.

Total Cholesterol (TC)

A total cholesterol level of 200 mg/dL is considered desirable; levels 200 to 240 indicate moderate risk for heart disease; levels 240 and above indicate a high risk for heart disease. Certain conditions can temporarily influence your total cholesterol level. Cholesterol levels rise during pregnancy and when using certain medications, including oral contraceptives and beta blockers. They can fall after an acute illness or stress, such as a heart attack. A very low cholesterol level can signal liver disease or cancer.

High-density Cholesterol (HDL-C )

HDL-C is known as the “good” cholesterol because high levels of HDL-C have been shown to protect against heart disease. HDL is thought to transport cholesterol out of the arteries to the liver, where it is broken down. HDL-C levels of 50 mg/dL are advised for women. The ratio of total cholesterol to HDL-C is also used to express risk of heart disease. In general, a ratio of 5:1 is advisable; a ratio of 3.5 or lower is optimum.

Low-density Cholesterol (LDL-C)

LDL-C is known as the “bad” cholesterol because it is the form that embeds in the artery walls to form the basis of atherosclerotic plaque. LDL-C levels of 100 mg/dL or less are considered optimal; 100 to 160 mg/dL indicate moderate risk; 160 mg/dL and above signal high risk of heart disease.

Triglycerides

Triglycerides are another type of fat molecule that is used to judge heart disease risk. A normal triglyceride level is 150 mg/dL or lower; 150 to 200 mg/dL, moderate risk; 200 mg/dL and higher, high risk.

Learning Your Results

The laboratory will forward the results to your doctor, who will discuss them with you, usually within a week or two. If they are less than optimal, you and your doctor can discuss a plan to improve your lipid profile.

Date Last Modified: January 21, 2011

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