The test of HDL cholesterol is used to help find out your risk of developing 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.

HDL cholesterol as part of the lipid profile may be requested more frequently for those who have one or more risk factors for heart disease. Major risk factors include:

Cigarette smoking

Age (men over 45 year and women over 55 years)

Hypertension (blood pressure 140/90 or higher or taking medications for high blood pressure)

For children and adolescents at low risk, lipid testing is not requested routinely. However, screening with a lipid profile is recommended for children and youths who are at an increased risk of developing heart disease. Some of the risk factors in children and young people are the same as those in adults and include a family history of heart disease, diabetes, high blood pressure or being overweight. HDL cholesterol levels may be requested at intervals to evaluate lifestyle changes such as diet and exercise or smoking cessation aimed at increasing your level of HDL cholesterol.

High levels of HDL cholesterol are better than low HDL cholesterol.  The higher your HDL cholesterol level, the lower risk of developing heart disease. 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 cholesterol is less than 1.0 mmol/L in men or less than 1.2 mmol/L in women, there is an increased risk of heart disease. A desirable level of HDL is greater than 1.0 mmol/L for men and greater than 1.2mmol/L for women 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 suddenly unwell. Cholesterol is temporarily low during sudden 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.