Total Cholesterol
Total cholesterol is a single number that adds up all the cholesterol in your blood — the protective kind, the kind linked to heart disease, and a few smaller fractions. You are probably hoping for a simple "is my number OK?", and the honest answer is that there is no single safe number for everyone in Australia. What matters is your result together with your age, blood pressure, smoking, and other risks, which your GP combines to work out your personal heart-health picture. This page helps you understand your number and know what to ask.
Standard CareAustralian adults have a total cholesterol considered high (5.5 mmol/L or above), based on the 2011–12 Australian Health Survey.
What is total cholesterol?
Total cholesterol is the sum of all cholesterol carried by lipoproteins — tiny particles that ferry cholesterol through your bloodstream. It combines three main pieces: HDL cholesterol (the protective form that helps clear cholesterol away from artery walls), LDL cholesterol (the form that can build up inside artery walls), and a few smaller fractions. Cholesterol itself is essential — your body needs it to build cell membranes and produce hormones. The problem arises when there is too much of the LDL-carrying kind: over time, the excess can settle into artery walls and slowly narrow the vessels — doctors call this atherosclerosis — which is what raises the risk of heart attack and stroke. Total cholesterol is usually reported as part of a full lipid profile alongside HDL, LDL, and triglycerides.
Why is it tested?
Total cholesterol is a key part of a cardiovascular disease (CVD) risk assessment — checking how likely you are to have a heart attack or stroke over the coming years. It is routinely ordered during health checks and as part of a Heart Health Check (generally from age 45, or earlier for Aboriginal and Torres Strait Islander peoples or where there is a family history). On its own the number only tells part of the story, so your GP feeds it into the Australian CVD risk calculator alongside your age, sex, blood pressure, diabetes status, and smoking — giving your real, personal risk rather than a line in the sand. The test is also used to check whether cholesterol-lowering treatment is having a measurable impact.
Reference range (Australia)
Australia uses absolute CVD risk assessment rather than a single total-cholesterol target — the Heart Foundation notes there is no "one-size-fits-all" number. The 5.5 mmol/L figure is a population definition of "high", not a personal target. The 2023 CVD risk guideline flags a total cholesterol of 7.5 mmol/L or above as a reason to consider higher-risk assessment regardless of the calculated score. Use the interval on your report and your GP's risk assessment.
Reference intervals vary between laboratories. Always use the range printed on your own report.
What your result means
A below-range total cholesterol is uncommon and is usually not concerning on its own. Very low cholesterol can occasionally reflect malabsorption, liver disease, an overactive thyroid (hyperthyroidism), or a very low-fat diet. Your GP can tell you which is more likely for you by looking at the full picture alongside your other results.
A result below the population threshold is reassuring, but it does not automatically mean your cardiovascular risk is low. Australian guidelines assess risk using your whole picture — cholesterol is just one piece. If you have other risk factors such as high blood pressure, smoking, or a family history of early heart disease, your GP may still want to talk through your overall CVD risk at your next check-up.
A total cholesterol of 5.5 mmol/L or above is what Australian surveys use to define "high" — but it does not, by itself, mean you have heart disease, and it is not the number your GP acts on alone. What it does signal is that your lipid profile may be adding to your cardiovascular risk, and that it is worth looking at the whole picture. Your GP will work out your absolute CVD risk — which folds in your age, blood pressure, smoking, and other factors — to decide whether any action is needed. Common reasons for a raised result include diet, genetics, physical inactivity, and excess weight. Conditions such as an underactive thyroid (hypothyroidism) can also push cholesterol up. If your total cholesterol is very high (more than 7.5 mmol/L), your GP may look into familial hypercholesterolaemia (FH) — an inherited condition where cholesterol runs high from birth regardless of diet. Depending on your overall risk, they may suggest lifestyle changes, medication, or both. Worth raising at your next visit.
What can affect your result
Several things shape your total cholesterol, and some are more in your control than others. Diet has one of the biggest effects: saturated and trans fats are associated with higher cholesterol, while unsaturated fats, more fibre, and a Mediterranean-style pattern are associated with lower levels. Regular activity and a healthy weight are linked with lower cholesterol too. Genetics matter just as much. Familial hypercholesterolaemia (FH) — an inherited condition affecting roughly 1 in 250 Australians — keeps cholesterol high regardless of diet, and usually needs medication as well as lifestyle changes. Conditions that are worth knowing about include an underactive thyroid (hypothyroidism), kidney disease, and metabolic syndrome (a cluster of conditions — raised blood sugar, blood pressure, and abdominal fat — that together raise heart risk). Some medicines, including certain hormone therapies, can also affect cholesterol levels. Statins are a widely used cholesterol-lowering medicine your GP may discuss when lifestyle changes alone are not enough.
When to act
If your total cholesterol is raised, that is the start of a conversation rather than a reason to panic. Your GP will use the Australian CVD risk calculator to work out your absolute 5-year risk — folding in your age, blood pressure, smoking, diabetes, and other factors — and then decide together with you whether lifestyle changes, medication, or both make sense. The decision is based on your overall risk, not your cholesterol number alone. If you have a family history of very high cholesterol or early heart disease, it is worth mentioning, as this may point to familial hypercholesterolaemia (FH). And if your result is in-range, that is generally good news — but other risk factors can still make a check-in with your GP worthwhile. This page is general information and is not a substitute for advice from your GP.
Frequently asked questions
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