Cholesterol and Blood Fat Terms
What LDL, HDL, non-HDL, triglycerides and the other lipid words actually mean.
Last revised
The vocabulary of a lipid panel and the conversation that follows it, defined plainly.
The fractions
Cholesterol is a fat-like substance essential to cell membranes and hormone production, carried in the blood by lipoproteins. LDL, low-density lipoprotein, carries cholesterol to tissues and is the fraction most strongly linked to arterial disease. HDL, high-density lipoprotein, carries it back to the liver. Non-HDL is total cholesterol minus HDL, capturing all the potentially harmful fractions in one figure.
Other measured values
Triglycerides are a different type of blood fat, raised by excess alcohol, refined carbohydrate and poorly controlled diabetes. The total-to-HDL ratio expresses the balance between them. Lipoprotein(a), or Lp(a), is an inherited and largely unmodifiable particle increasingly measured in people with a strong family history.
The conditions
Hyperlipidaemia means raised blood fats generally. Familial hypercholesterolaemia is an inherited condition causing very high LDL from birth, affecting roughly one in 250 people and substantially underdiagnosed. Atherosclerosis is the process by which fatty plaques build in artery walls, and is what the numbers are ultimately about.
The treatments and tools
Statins inhibit cholesterol production in the liver. Ezetimibe reduces absorption from the gut. PCSK9 inhibitors and inclisiran are injectable treatments used in specialist settings. QRISK is the tool used in the UK to estimate ten-year cardiovascular risk, combining cholesterol with age, sex, blood pressure, smoking, diabetes, ethnicity and family history.
At a glance
| Term | Detail |
|---|---|
| LDL | low-density lipoprotein; the fraction most linked to arterial disease |
| HDL | high-density lipoprotein; carries cholesterol back to the liver |
| Non-HDL | total cholesterol minus HDL |
| Triglycerides | a separate blood fat, raised by alcohol and refined carbohydrate |
| Lp(a) | an inherited, largely unmodifiable particle |
| Familial hypercholesterolaemia | inherited very high LDL; roughly 1 in 250 people |
| Atherosclerosis | fatty plaque build-up in artery walls |
| QRISK | the UK 10-year cardiovascular risk tool |
When to get help
See a GP if you have a family history of heart attack or stroke before 60, or fatty deposits around the eyes or in tendons, which can indicate familial hypercholesterolaemia. Call 999 for chest pain lasting more than a few minutes, or sudden weakness or numbness on one side.
Where to go next
Where this comes from
- NICE - Cardiovascular disease: risk assessment and reduction, including lipid modification
- HEART UK - cholesterol glossary
- NHS - High cholesterol
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.