Cholesterol Explained: What LDL, HDL and Your Test Results Mean in November 2026

Information checked: November 6, 2026, at 01:09 UTC.

A cholesterol test can help estimate your risk of heart attack and stroke, but the total cholesterol number is only part of the picture. LDL, HDL and triglycerides each tell your clinician something different, and the result that calls for action depends on your overall cardiovascular risk.

For readers in Australia, results are usually reported in millimoles per liter (mmol/L). If a number is flagged on your report, arrange to discuss it with your doctor: a laboratory reference range and your personal treatment target are not necessarily the same.

Destaques

• LDL carries cholesterol that can contribute to plaque buildup in arteries; lowering elevated LDL can reduce cardiovascular risk.
• HDL helps carry cholesterol back to the liver, but a favorable HDL result does not cancel out a high LDL result.
• A lipid panel usually also reports total cholesterol and triglycerides, and may include non-HDL cholesterol.
• Your doctor interprets the numbers alongside factors such as blood pressure, smoking, diabetes and family history.

What is cholesterol, and why does it matter?

Cholesterol is a waxy substance your body needs for functions including making cells and hormones. Your liver makes cholesterol, and some foods contain it too. Because cholesterol does not travel freely through blood, it is carried in particles called lipoproteins.

Problems can develop when cholesterol accumulates in artery walls as part of fatty deposits called plaque. Plaque can narrow arteries or rupture and cause a clot, leading to a heart attack or stroke. High cholesterol usually causes no obvious symptoms, so a blood test is the way to find out your levels. The Heart Foundation explains cholesterol and cardiovascular risk.

What is the difference between LDL and HDL cholesterol?

LDL cholesterol is often called “bad” cholesterol because excess LDL contributes to cholesterol buildup in artery walls. A higher LDL level generally means greater long-term risk, although the treatment decision depends on the whole clinical picture.

HDL cholesterol is often called “good” cholesterol because HDL helps transport cholesterol away from arteries and back to the liver. Higher HDL is generally associated with lower risk, but it is not a guarantee of protection. Your clinician will still pay attention to LDL and other risk factors.

How do you read a cholesterol blood test?

A lipid panel usually includes the following measurements. Your report may include additional calculations or a laboratory reference range.

• Total cholesterol: the cholesterol carried in several kinds of particles, including LDL and HDL. It is useful as a starting point but cannot show the whole pattern by itself.
• LDL cholesterol: a key measure used when considering cholesterol-lowering treatment and monitoring its effect.
• HDL cholesterol: one part of the risk assessment, interpreted alongside the other results.
• Triglycerides: another type of blood fat. High triglycerides, especially alongside high LDL or low HDL, can add to cardiovascular risk.
• Non-HDL cholesterol: total cholesterol minus HDL cholesterol. It captures cholesterol carried by LDL and other particles that can contribute to plaque.

For example, if total cholesterol is 5.5 mmol/L and HDL is 1.5 mmol/L, non-HDL cholesterol is 4.0 mmol/L. That calculation describes the result; it does not by itself tell you whether you need medication. Ask your doctor what each value means for you. See healthdirect’s guide to lipid tests for more on the measurements.

What cholesterol level should you aim for?

There is no single LDL target that fits everyone. A person who has already had a heart attack may have a different treatment goal from someone without known cardiovascular disease. Age, blood pressure, smoking, diabetes, kidney disease, family history and other factors also matter.

In Australia, a Heart Health Check can bring these factors together to estimate cardiovascular risk and guide a prevention plan. Some conditions or very high results may also warrant particular attention. Ask your doctor whether a risk assessment applies to you, what your individual LDL goal is and when your levels should be checked again. The Heart Foundation’s Heart Health Check guide describes the assessment.

What causes high cholesterol?

Genes can play a significant role, as can age, diet and other health conditions. Saturated and trans fats can raise LDL cholesterol. Some people inherit familial hypercholesterolemia, which can cause high LDL from a young age. Tell your doctor if close relatives have very high cholesterol or developed heart disease early; this may affect whether you or family members need further assessment.

Triglycerides can also rise for several reasons, including poorly managed diabetes, alcohol intake and some dietary patterns. Your doctor can consider possible causes and whether a repeat test or further investigation is appropriate.

What can you do if your cholesterol is high?

Start by reviewing your result with your doctor rather than relying on a single flagged number. Depending on your circumstances, useful changes can include replacing saturated fats with unsaturated fats, eating more vegetables, legumes and whole grains, being physically active, stopping smoking and limiting alcohol. A dietitian can help turn these ideas into a practical eating plan.

Some people also benefit from cholesterol-lowering medicine, such as a statin, to reduce their risk of heart attack and stroke. The decision depends on overall risk, possible benefits and side effects, and your preferences. If you already take a medicine, do not stop or change it without discussing the decision with your clinician. A follow-up blood test can show how well the agreed plan is working.

Frequently asked questions

Do I need to fast before a cholesterol test?

Not always. Both fasting and nonfasting lipid tests can be suitable. Ask your doctor or pathology collection center for instructions, and tell your clinician whether you fasted when interpreting the result.

Can high HDL make a high LDL result harmless?

No. HDL is only one part of the assessment. High LDL can still contribute to plaque buildup, so discuss both values and your other risk factors with your doctor.

How often should I have my cholesterol checked?

That depends on your age, health history and whether you are receiving treatment. The Heart Foundation advises people aged 45 or older, or 30 or older for Aboriginal and Torres Strait Islander people, to see a doctor for a cholesterol test as part of a Heart Health Check. Your doctor may recommend earlier or more frequent testing based on your circumstances.