High cholesterol usually means a raised LDL (“bad”) cholesterol, which builds up in artery walls over many years and raises the risk of heart attack and stroke. If you do not have heart disease, there is no Australian LDL target: treatment is based on your 5-year risk. If you have established coronary disease or have had a heart attack, the goal is an LDL below 1.4 mmol/L and at least a 50% reduction (NHFA/CSANZ 2025; ESC 2024).
What cholesterol is
Cholesterol is a natural, waxy substance found in every cell of your body. You need it to build cell walls and to make hormones, vitamin D and bile (which helps you digest fat). Your liver makes most of it, and a smaller amount comes from food.
The problem is atherosclerosis: the slow build-up of fatty plaque inside the arteries, which can lead to heart attack and stroke. Risk depends on how high your LDL is and on how many years it stays high, so lowering it earlier lowers your lifetime risk.
The different types of cholesterol
Cholesterol travels in your blood inside particles called lipoproteins. Each type means something different for your heart.
LDL cholesterol
Often called “bad” cholesterol. LDL carries cholesterol to the rest of the body, including the artery walls. When it stays high for years, plaque builds up. There is no single normal level that suits everyone.
HDL cholesterol
Often called “good” cholesterol. HDL carries extra cholesterol back to the liver. A healthy level is generally above 1.0 mmol/L in men and above 1.3 mmol/L in women.
Triglycerides
The main type of fat in the blood, used for energy. Raised levels, especially with a low HDL, are linked with more heart disease. A normal level is generally below 1.7 mmol/L.
How your overall risk is worked out
For people without heart disease, treatment is based on your 5-year risk from the Australian CVD risk calculator (AusCVDRisk). Your GP enters your age, sex, smoking, blood pressure, the ratio of total to HDL cholesterol, diabetes, atrial fibrillation (an irregular heart rhythm), a postcode-based measure of disadvantage and your current medicines.
Chance of a heart attack or stroke in the next 5 years. Source: 2023 Australian guideline for assessing and managing CVD risk.
You are treated as high risk without the calculator if you have:
- known heart or blood vessel disease, such as a past heart attack, stent or stroke
- confirmed familial hypercholesterolaemia (FH, an inherited cause of high cholesterol)
- moderate to severe chronic kidney disease (eGFR below 45, or a urine albumin-to-creatinine ratio above 25 mg/mmol in men or above 35 mg/mmol in women)
Medication is also usually recommended, whatever the calculator shows, if your total cholesterol is above 7.5 mmol/L or your blood pressure is above 160/100.
Your doctor can move your result up or down a risk group. A family history of early heart disease may move you higher. A coronary calcium score can help when the decision is uncertain (see below).
LDL goals
Whether you have an LDL goal depends on whether you already have heart disease.
No heart disease
There is no Australian LDL target. Treatment is based on your 5-year risk, as above.
Established coronary disease or after a heart attack
LDL below 1.4 mmol/L and at least a 50% reduction from your starting level. This includes people whose CT coronary angiogram shows plaque that narrows an artery. For non-obstructive plaque, Dr Ng usually aims for LDL below 1.8 mmol/L, or below 1.4 mmol/L in people at higher risk.
Sources: NHFA/CSANZ acute coronary syndrome guideline 2025; ESC chronic coronary syndromes guideline 2024. European guidelines also set LDL goals for people without heart disease, and you may see these on some reports. In Australia, your 5-year risk guides treatment instead.
Advanced cholesterol markers
A standard cholesterol test is the right first step for most people. Extra tests can help if you have a strong family history, diabetes or raised triglycerides, or if a treatment decision is not clear-cut.
Non-HDL cholesterol
Your total cholesterol minus your HDL. It counts all the cholesterol in plaque-forming particles, so it is useful when triglycerides are raised. It appears on most Australian lipid reports at no extra cost.
Apolipoprotein B (ApoB)
ApoB counts the number of plaque-forming particles, because each one carries exactly one ApoB molecule. When triglycerides are raised, it can reflect risk better than LDL.
Lipoprotein(a)
Lipoprotein(a), written Lp(a), is a cholesterol particle whose level is mostly inherited. Diet, exercise and standard cholesterol tablets hardly change it. Below about 75 nmol/L it is unlikely to add risk, about 75–125 nmol/L is borderline, and above about 125 nmol/L it raises your risk of heart attack and stroke (EAS 2022).
As of October 2026, European (ESC/EAS 2025) and American (ACC/AHA 2026) guidelines recommend measuring Lp(a) at least once in adulthood. The 2023 Australian guideline does not use Lp(a) to adjust risk, and Medicare does not rebate the test, so there is usually a small out-of-pocket cost. If your level is high, the focus is on keeping your LDL and other risk factors well controlled.
What causes high cholesterol
High cholesterol usually reflects a mix of the genes you inherit, lifestyle and, sometimes, another medical condition.
Genes
Familial hypercholesterolaemia affects about 1 in 250 people and often gives an LDL of 5.0 mmol/L or higher from a young age. More often, many small genetic differences add together and raise cholesterol even with a healthy lifestyle.
Lifestyle
Diets high in saturated and trans fats raise LDL over time. Inactivity, extra weight and smoking add to overall risk. Small, lasting changes help.
Other conditions and medicines
An underactive thyroid, kidney disease, diabetes, liver conditions and some medicines (such as corticosteroids) can raise cholesterol. Treating the cause can improve your levels.
Having your cholesterol tested
Testing usually starts with a standard lipid profile: total cholesterol, LDL, HDL and triglycerides. Most people do not need to fast.
- Adults aged 45 to 79 (from 35 with diabetes, and from 30 for Aboriginal and Torres Strait Islander people): a heart risk check that includes cholesterol.
- Younger adults with risk factors, such as a family history of heart disease.
- After starting or changing treatment: usually 4 to 12 weeks later.
- Ongoing: every 3 to 12 months, depending on your risk and treatment.
A coronary calcium score (a low-dose CT scan of the heart arteries) can help some people without symptoms whose risk group is uncertain. A score of 0 may move you to a lower risk group; a score above 99, or at or above the 75th percentile for your age and sex, may move you higher, where treatment is usually recommended; a score of 1–99 below the 75th percentile is discussed with your doctor. It is not a routine screening test and you pay for it, so it is most useful when the result would change your treatment. See what your calcium score result means.
When medication is recommended
A heart-healthy lifestyle is the foundation for everyone. Medication is added when the expected benefit clearly outweighs the risks, which depends on your overall risk rather than your cholesterol alone.
Medication is usually recommended if you are in a high-risk group or your 5-year risk is 10% or more, and discussed with you at 5% to under 10% (see the risk groups above). If your risk is low, lifestyle changes are often enough, with regular checks in case your risk changes.
An untreated LDL of 5.0 mmol/L or higher in an adult should prompt a check for familial hypercholesterolaemia.
Statins are the most studied cholesterol medicines. In large trials, lowering LDL by about 2 mmol/L for 5 years prevented a heart attack, stroke or similar event in about 10 in 100 people with existing heart or blood vessel disease, and about 5 in 100 people at increased risk without it (Collins, Lancet 2016). In blinded trials, only about 1 in 100 people had muscle aches caused by the statin itself (CTT, Lancet 2022). Read more in statins explained.
Other options include ezetimibe tablets, and injectable LDL-lowering medicines for some people at high risk whose LDL stays high despite tablets. Ask your doctor which are available to you on the PBS.
Frequently asked questions
Do I need to fast before a cholesterol test?
Usually not. Your doctor may ask you to fast if your triglycerides were very high on a previous test.
Can high cholesterol run in families?
Yes. Familial hypercholesterolaemia affects about 1 in 250 people. If it is found, close relatives should be tested too.
For referring doctorsClinical notes for GPs
- Refer when: suspected FH (Dutch Lipid Clinic Network score 6 or more), LDL above the goal stated in Dr Ng's letter on statin plus ezetimibe, intolerance to two or more statins, triglycerides above 10 mmol/L, or high Lp(a) with premature CVD.
- Send: non-fasting lipids, TSH, LFTs, eGFR and urine ACR, HbA1c, AusCVDRisk score, family history, and one Lp(a) in nmol/L if done (not MBS-rebated).
- Medicines: recommend lipid-lowering at 10% or more 5-year AusCVDRisk; consider at 5–<10%. Clinically high risk without the calculator: known CVD, confirmed FH, moderate-to-severe CKD (sustained eGFR <45 and/or persistent uACR >25 mg/mmol men, >35 mg/mmol women). Treat irrespective of calculated risk if TC >7.5 mmol/L or BP >160/100. (2023 Australian CVD risk guideline)
- Reclassification: CAC 0 may reclassify lower; CAC >99 or ≥75th percentile for age and sex may reclassify higher, where treatment is usually recommended; 1–99 below the 75th percentile: individualise (2023 guideline; NHFA CAC position statement, MJA 2021). Family history of premature CVD can reclassify higher. the 2023 Australian guideline does not use Lp(a) to adjust risk.
- Targets and monitoring: no Australian LDL target in primary prevention; treat on 5-year risk. Established coronary disease (including obstructive plaque on CTCA) and after ACS: LDL below 1.4 mmol/L and at least a 50% reduction (ESC 2024 chronic coronary syndromes guideline; after ACS, NHFA/CSANZ 2025). Non-obstructive plaque on CTCA: Dr Ng usually aims for LDL below 1.8 mmol/L, or below 1.4 mmol/L in people at higher risk. Recheck lipids 4–12 weeks after a change, then every 3–12 months. No routine CK or LFT monitoring without symptoms.
- PBS/MBS: statins and ezetimibe are Unrestricted Benefits. Evolocumab and inclisiran (inclisiran listed 1 April 2024) are Authority Required for HeFH or established ASCVD above PBS LDL thresholds despite maximally tolerated statin plus ezetimibe. Bempedoic acid was considered by the PBAC in July 2026; as of October 2026 it is not PBS-listed, so check current status.
General information for referring practitioners. Check current MBS and PBS criteria before acting.
References
- Nelson MR, Banks E, Brown A, et al. 2023 Australian guideline for assessing and managing cardiovascular disease risk. Med J Aust. 2024;220(9):482-490. doi:10.5694/mja2.52280
- Jennings GLR, Audehm R, Bishop W, et al. National Heart Foundation of Australia: position statement on coronary artery calcium scoring for the primary prevention of cardiovascular disease in Australia. Med J Aust. 2021;214(9):434-439. doi:10.5694/mja2.51039
- Brieger D, et al. National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand: Australian clinical guideline for diagnosing and managing acute coronary syndromes 2025. Med J Aust. 2026;224(2). doi:10.5694/mja2.70127
- Vrints C, Andreotti F, Koskinas KC, et al. 2024 ESC Guidelines for the management of chronic coronary syndromes. Eur Heart J. 2024;45(36):3415-3537. doi:10.1093/eurheartj/ehae177
- Mach F, Baigent C, Catapano AL, et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias. Eur Heart J. 2020;41(1):111-188. doi:10.1093/eurheartj/ehz455
- Mach F, Koskinas KC, Roeters van Lennep JE, et al. 2025 Focused Update of the 2019 ESC/EAS Guidelines for the management of dyslipidaemias. Eur Heart J. 2025;46(42):4359-4378. doi:10.1093/eurheartj/ehaf190
- Kronenberg F, Mora S, Stroes ESG, et al. Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic stenosis: a European Atherosclerosis Society consensus statement. Eur Heart J. 2022;43(39):3925-3946. doi:10.1093/eurheartj/ehac361
- American College of Cardiology/American Heart Association. 2026 ACC/AHA/Multisociety guideline on the management of dyslipidemia. Circulation and J Am Coll Cardiol. 2026.
- Collins R, Reith C, Emberson J, et al. Interpretation of the evidence for the efficacy and safety of statin therapy. Lancet. 2016;388(10059):2532-2561. doi:10.1016/S0140-6736(16)31357-5
- Cholesterol Treatment Trialists' Collaboration. Effect of statin therapy on muscle symptoms: an individual participant data meta-analysis of large-scale, randomised, double-blind trials. Lancet. 2022;400(10355):832-845. doi:10.1016/S0140-6736(22)01545-8