HDL Cholesterol Test
Aged 40 as part of a routine cardiovascular health check, or if you are already thought to be at risk of cardiovascular disease for another reason.
A blood sample taken from a vein in the arm or from a finger-prick
No fasting is needed for an HDL-cholesterol test. However, you should follow your doctor's advice as fasting might be needed for other tests being performed.
HDL is one of the classes of lipoproteins that carry cholesterol in the blood. HDL is thought to be beneficial because it removes excess cholesterol from tissues and carries it to the liver for disposal. Hence HDL cholesterol is often called “good” cholesterol. The test for HDL measures the amount of cholesterol carried on HDL particles in blood.
How is the sample collected for testing?
Testing for HDL cholesterol requires a blood sample. Most often, the blood sample is collected by venepuncture (using a needle to collect blood from a vein in the arm). Occasionally a fingerprick test can be used, although this is not commonly available in GP practices or hospitals in the UK.
Is any test preparation needed to ensure the quality of the sample?
No fasting is needed for an HDL-cholesterol test. In the past, a full lipid profile (which includes HDL-cholesterol) would require fasting, but this changed in 2014. However, even the full lipid profile no longer requires fasting. On the other hand, there may be circumstances when fasting is still required, so you should follow instructions given by your doctor.
How is it used?
HDL-cholesterol testing is usually used to help find out your risk of developing cardiovascular disease. If you have a high cholesterol, your doctor may wish to know if this is mainly due to non-HDL cholesterol (bad) or to HDL-cholesterol (good). Usually it due to having high non-HDL cholesterol, unfortunately.
Your HDL-cholesterol can be used, along with total cholesterol and other factors, in "risk calculators" such as QRISK2, which estimate your future risk of getting cardiovascular disease. The value which is entered into the calculator is actually the "total cholesterol to HDL-C ratio", ie the balance between total cholesterol and good cholesterol. Knowing your future risk can guide decisions on making lifestyle changes or starting medical treatments.
When is it requested?
HDL is usually requested with other tests, either with cholesterol or as part of a lipid profile, including non-HDL and triglycerides. This is done during a routine cardiovascular risk assessment, which GPs offer to people aged 40 or over. If your doctor thinks you could be at higher risk of cardiovascular disease for another reason, they may recommend HDL testing at other times.
What does the test result mean?
High levels of HDL cholesterol are better than low HDL cholesterol. The higher your HDL cholesterol level, the lower risk of developing cardiovascular disease. This is because HDL carries cholesterol away from the artery walls and back to the liver, where it is eliminated.
Other factors can affect your HDL cholesterol result. For example, physical exercise and moderate alcohol consumption increase your HDL cholesterol, whereas smoking reduces it.
Is there anything else I should know?
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.
My HDL is high. Is this a problem?