The test of HDL cholesterol is used to determine your risk of heart disease. If a high cholesterol is due to high HDL, a person is probably at low risk and further testing or treatment for high cholesterol is not advised.

HDL is usually requested with other tests, either with cholesterol or as part of a lipid profile, including LDL and triglycerides. The combination of total cholesterol and HDL is very useful for screening for the risk ofheart disease since it is not necessary to fast for these two tests. In contrast, a more complete lipid profile requires fasting for at least 12 hours

High HDL is better than low HDL. There are two ways that HDL cholesterol values are interpreted—as a percent of total cholesterol or as a measured value.

• Percent: If HDL is 20% of the total cholesterol, the risk of heart disease is average. If HDL is more than 20% of the total cholesterol, the risk of heart disease is less than average. This is usually expressed as a ratio of cholesterol to HDL. It is desirable for the cholesterol/HDL ratio to be less than 5.
• Measured Value: If HDL is less than 1.0 mmol/L, there is an increased risk of heart disease. A desirable level of HDL is greater than 1.0 mmol/L and is associated with average risk of heart disease. A good level of HDL is 1.5 mmol/L or more and is associated with a less than average risk of heart disease.

HDL should be interpreted in the context of the overall findings from the lipid profile and in consultation with your doctor about other risk factors for heart disease.

HDL cholesterol should not be measured when a person is unwell. Cholesterol is temporarily low during acute illness, immediately following a heart attack, or during stress (like from surgery or an accident). You should wait at least 6 weeks after any illness to have cholesterol measured.

In women, HDL cholesterol may change during pregnancy. You should wait at least six weeks after your baby is born to have your HDL-cholesterol measured.