HDL Cholesterol
HDL is the "good" cholesterol — it acts like a clean-up crew, picking up cholesterol from your arteries and carrying it to the liver to be broken down. Unlike most blood markers, you are hoping for a higher number, not a lower one: a low HDL is the direction that raises concern. If you are wondering whether your result is OK, the honest answer is that HDL is one piece of your heart-risk picture — your GP reads it alongside your other cholesterol markers, blood pressure, and lifestyle to make sense of the whole.
Standard CareAustralian adults have low HDL cholesterol (below 1.0 mmol/L for men, below 1.3 mmol/L for women), based on the 2011–12 Australian Health Survey.
What is hdl cholesterol?
HDL stands for high-density lipoprotein — think of it as your bloodstream's clean-up crew. Where LDL (low-density lipoprotein, the "bad" cholesterol) can settle into artery walls and form plaque over time, HDL does the reverse: it picks up excess cholesterol from your arteries and carries it back to the liver, where it is broken down and cleared. That process is called reverse cholesterol transport, and it is why HDL is labelled the "good" cholesterol. HDL is measured as part of a lipid panel — a blood test that looks at your HDL, LDL, total cholesterol, and triglycerides together. Your GP uses that full picture to assess your cardiovascular risk, not any single number in isolation.
Why is it tested?
HDL cholesterol is measured as part of routine cardiovascular screening and lipid assessment. What makes it unusual is that a higher result is generally protective — the opposite of most markers where a high reading signals trouble. Australian guidelines feed HDL (and the ratio of total cholesterol to HDL) into the national absolute cardiovascular disease (CVD) risk calculator at cvdcheck.org.au, alongside your age, blood pressure, smoking status, diabetes, and family history. That calculation produces your estimated likelihood of a heart attack or stroke over the next five years — your GP uses this figure to set priorities, not any single cholesterol number on its own.
Reference range (Australia)
Australian sources define low HDL as below 1.0 mmol/L in men and below 1.3 mmol/L in women, so levels above these are protective (AIHW; ABS citing RCPA 2024). For HDL, low is the concerning direction and higher is generally protective — the reverse of LDL. The reference interval on your own report is the most relevant guide, and a single in-range HDL is reassuring but not the whole risk picture.
Reference intervals vary between laboratories. Always use the range printed on your own report.
What your result means
A result below 1.0 mmol/L for men, or below 1.3 mmol/L for women, is the concerning direction for HDL — the opposite of most blood tests, where a high value raises the alarm. Low HDL means fewer protective particles circulating, and is associated with higher cardiovascular risk. Low HDL can reflect physical inactivity, smoking, excess weight (particularly around the abdomen), diet, certain medicines, or genetics. Your GP will look at the full risk picture before suggesting any next steps; a single low result is a starting point for a conversation, not a verdict.
An in-range HDL is reassuring — it suggests this marker is not adding to your cardiovascular risk. Your overall heart risk still depends on your LDL, triglycerides, total cholesterol, blood pressure, age, and other factors. Your GP weighs those together using the Australian CVD risk calculator to give you a complete picture.
A higher HDL — generally above 1.0 mmol/L for men and 1.3 mmol/L for women — is usually good news. It means more cholesterol-removing particles are at work, and is associated with lower cardiovascular disease (CVD) risk. That said, very high HDL does not appear to add further protection beyond a certain point; recent evidence suggests the relationship is U-shaped rather than simply "higher is always better". Your GP interprets your HDL result alongside your full lipid panel and other risk factors, not as a standalone figure.
What can affect your result
Several lifestyle factors and some medicines affect HDL. Regular aerobic activity is one of the factors most consistently associated with higher HDL over time. On the lowering side: smoking is associated with lower HDL, and so are carrying extra weight (particularly around the abdomen) and being physically inactive. Some medicines can lower it too — some beta blockers and diuretics are recognised examples — so it is worth telling your GP what you take when they read the result. Genetics play a meaningful role as well. Some people naturally run higher or lower HDL regardless of their lifestyle — worth mentioning to your GP if HDL stays low despite other changes.
When to act
If your HDL is below the protective threshold, it is worth raising at your next GP visit. Rather than focusing on HDL alone, your GP will assess your overall cardiovascular risk and may suggest lifestyle changes — regular aerobic activity, a heart-healthy diet, reaching a healthy weight, and not smoking. If you take medicines that can lower HDL, let your GP know so they can consider whether alternatives suit you. If your GP recommends repeat testing after a few months, it can show whether lifestyle changes are having an effect. If your HDL is in range or above, keeping up your current habits and continuing routine monitoring is the right approach — a healthy HDL can drift if circumstances change. This page is general information and is not a substitute for advice from your GP.
Frequently asked questions
Test your hdl cholesterol
NATA-accredited testing. Results in 2–5 days. No GP referral required.
View Lipids