The test for HDL cholesterol (HDL-C) is used along with other lipid tests to screen for unhealthy levels of lipids and to determine your risk of developing heart disease.

Your HDL-C level may also be monitored by your doctor on a regular basis if previous test results have shown you to have an increased risk for heart disease or if you have had a heart attack or if you are undergoing treatment for high cholesterol levels.

HDL-C may be ordered as a follow up test to a high result on a cholesterol screening test. HDL-C is usually not ordered by itself but with other tests, including cholesterol, LDL cholesterol (LDL-C), and triglycerides as part of a lipid profile during a health check-up. It is recommended that all adults be tested at least once every five years.

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

• Cigarette smoking
• Age (men 45 years or older or women 55 years or older)
• Hypertension (blood pressure of 140/90 or higher or taking high blood pressure medications)
• Family history of premature heart disease (heart disease in an immediate family member—male relative under age 55 or female relative under age 65)
• Pre-existing heart disease or already having had a heart attack
• Diabetes mellitus

For children and adolescents at low risk, lipid testing is usually not ordered routinely. However, screening with a lipid profile is recommended for children and youths who are at an increased risk of developing heart disease as adults. Some of the risk factors are similar to those in adults and include a family history of heart disease or health problems such as diabetes, high blood pressure, or being overweight. High-risk children should have their first lipid profile (including HDL-C) between 2 and 10 years old, according to the American Academy of Pediatrics. Children younger than 2 years old are too young to be tested.

HDL-C levels may also be ordered at regular intervals to evaluate the success of lifestyle changes such as diet and exercise or smoking cessation aimed at increasing your level of HDL-C.

High levels of HDL-C are better than low HDL-C. The higher your HDL-C, the lower your risk of developing heart disease. For adults:

• If HDL-C is less than 40 mg/dL (1.0 mmol/L) for men and less than 50 mg/dL (1.3 mmol/L) for women, there is an increased risk of heart disease.
• A more desirable level of HDL-C is between 40-50 mg/dL (1.0-1.3 mmol/L) for men and between 50-59 mg/dl (1.3-1.5 mmol/L) for women and is associated with average risk of heart disease.
• The healthiest level of HDL-C is 60 mg/dL (1.55 mmol/L) or higher and is associated with a less than average risk of heart disease.

The risk categories for children and adolescents are different than adults. Talk to your child’s pediatrician about your child’s results.

Some laboratories report a ratio of total cholesterol to HDL cholesterol. The ratio is obtained by dividing the total cholesterol by the HDL cholesterol. For example, if a person has a total cholesterol result of 200 mg/dL and an HDL cholesterol level of 50 mg/dL, the ratio would be stated as 4 (or 4:1). A desirable ratio is below 5 (5:1); the optimum ratio is 3.5 (3.5:1). The American Heart Association recommends that the absolute numbers for total blood cholesterol and HDL cholesterol levels be used because they are more useful than the ratio in determining appropriate treatment for patients.

HDL should be interpreted in the context of the overall findings from the lipid profile and in consultation with your doctor.

A complete lipid profile requires fasting for 9-12 hours. If the testing occurs when a person is not fasting, only the HDL-C and total cholesterol values may be used for risk assessment.

HDL cholesterol should be measured when a person is not ill. 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 six 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.