Quick answer
What is a cholesterol blood test?
A cholesterol blood test measures fats in your blood to help assess heart disease and stroke risk. Many labs now accept a non-fasting sample. High LDL may lead to lifestyle changes and, after a QRISK assessment, sometimes a statin. Results are interpreted with your wider risk, not as a single number in isolation.
What a cholesterol blood test measures
A cholesterol blood test — often called a lipid profile — measures the main fats (lipids) in your blood:
- Total cholesterol
- LDL cholesterol — the type most linked to artery narrowing
- HDL cholesterol — generally protective
- Triglycerides — another blood fat linked to risk when raised
These numbers help estimate your chance of heart attack and stroke over the next 10 years, usually with a risk calculator such as QRISK in England.
Why the test is done
Cholesterol is checked if you have risk factors, as part of an NHS Health Check, before or during statin treatment, or if a close relative had early heart disease. High cholesterol usually causes no symptoms, so a blood test is the only reliable way to find it.
Fasting and how the test is done
A small sample is taken from a vein. Many people no longer need to fast for a routine lipid test. If you are asked to fast, water is usually allowed. Tell the person taking blood about medicines and recent illness, as these can affect results.
Understanding your results
Your GP looks at the whole picture. Someone with moderate cholesterol but diabetes or previous heart disease may need treatment more urgently than someone with a slightly higher reading but low overall risk.
Very high LDL, especially in younger adults or with a family history, should prompt thinking about familial hypercholesterolaemia.
Treatment after a high result
Lifestyle measures include reducing saturated fat, choosing unsaturated fats, eating oats and other soluble fibre, staying active, stopping smoking, and keeping to a healthy weight.
If medicine is advised, statins are usually first-line. They lower LDL and reduce event risk. Side effects are discussed before starting; most people tolerate treatment well. Other lipid-lowering medicines are sometimes added if targets are not met or statins are not suitable.
Follow-up
Repeat testing shows whether lifestyle changes or medicines are working. Do not stop a statin without medical advice because of a single blood result — discuss symptoms or concerns with a GP or pharmacist first.
Common questions about the cholesterol blood test
- Do I need to fast before a cholesterol blood test?
- For many routine lipid tests a non-fasting sample is now acceptable. Some situations still need fasting — for example when triglycerides are very high or your local lab asks for it. Follow the instructions you are given.
- What is a healthy cholesterol level?
- There is no single target for everyone. Treatment decisions usually combine your lipid results with age, blood pressure, smoking, diabetes and other factors using a tool such as QRISK. People with existing heart disease or diabetes often aim for lower LDL levels.
- Can diet alone lower cholesterol enough?
- Cutting saturated fat, eating more fibre, and keeping active can improve cholesterol. If your calculated risk is high, or you already have cardiovascular disease, a statin is often still recommended alongside lifestyle changes.
- What is familial hypercholesterolaemia?
- It is an inherited condition that causes very high LDL from a young age and raises early heart-attack risk. Clues include cholesterol that is very high, tendon xanthomas, or close relatives with early heart disease. It needs specialist assessment and usually medicine.
- How often should cholesterol be checked?
- After starting a statin, levels are often rechecked within about 3 months, then reviewed at least yearly once stable. If you are not on treatment, timing depends on your risk — your GP can advise.