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Plain-language information for patients

What is a cholesterol test?

A cholesterol or 'lipid' blood test measures several fats in your blood. They matter because high levels of some of them raise the long-term risk of heart attack and stroke.

What is measured?

The main results are total cholesterol, LDL ('bad' cholesterol, which furs up arteries), HDL ('good' cholesterol, which is protective), non-HDL cholesterol, and triglycerides (another type of fat). The ratio of total to HDL is also often reported.

There is no single 'normal' for everyone — what matters is your overall cardiovascular risk, which combines cholesterol with your age, blood pressure, smoking, diabetes and other factors.

What happens if it is high?

Your doctor will usually estimate your 10-year risk of heart disease and stroke (for example with QRISK) and discuss it with you. Lifestyle changes — diet, activity, stopping smoking — come first, and a statin may be offered if your risk is high enough.

Very high cholesterol, especially from a young age, can run in families (familial hypercholesterolaemia) and needs specific assessment.

Common questions

Do I need to fast before a cholesterol test?

Often not — most lipid tests can now be done without fasting. Your surgery will tell you if fasting is needed for your particular test.

Is all cholesterol bad?

No. HDL cholesterol is protective; it is mainly LDL and non-HDL cholesterol that raise risk. That is why doctors look at the breakdown, not just the total.

Related tools

These calculators are designed for healthcare professionals.

This page is general information, not personal medical advice, and does not replace a consultation with a qualified health professional. If you are worried about your health, please speak to your GP, pharmacist, or another clinician. Last reviewed 2026-06-08.