A cholesterol test, also called a lipid profile or lipogram, usually comes back as a short list of numbers: total cholesterol, HDL, LDL, sometimes non-HDL, and triglycerides. Each one tells you something different, and none of them means much on its own. Your doctor reads them together with your age, blood pressure, smoking, diabetes and family history to estimate your risk of a heart attack or stroke.

This guide explains what each number on the report means, the healthy levels that the NHS and the South African guideline use, how treatment targets work, and what to do next.

What a cholesterol test measures

A full lipid profile measures total cholesterol, HDL cholesterol and triglycerides in a blood sample. Two more numbers are usually worked out from these:

LDL cholesterol is usually calculated using a formula (the Friedewald formula), rather than measured directly.
Non-HDL cholesterol is simply total cholesterol minus HDL.

The units matter. The NHS, NICE and the South African guideline all use mmol/L. The American Heart Association reports results in mg/dL, and the numbers look completely different. Check the unit printed next to each result before comparing it with any chart, including the ones below, which are all in mmol/L.

What each number means

Total cholesterol

This is all the cholesterol in your blood added together. The NHS gives below 5 mmol/L as a healthy level for healthy adults. Total cholesterol is a rough guide. Two people with the same total can have very different risk, depending on how much of it is HDL.

HDL cholesterol ("good" cholesterol)

The NHS calls HDL "good cholesterol". Its healthy level is above 1.0 mmol/L for men and above 1.2 mmol/L for women.

LDL cholesterol ("bad" cholesterol)

LDL is the number that many treatment targets, including the South African guideline's, focus on. There is no single "normal" LDL, because the target depends on your risk:

Your risk level	LDL target (South African guideline, 2018)
Low or moderate risk	Below 3 mmol/L
High risk	Below 2.5 mmol/L, and at least a 50% reduction if your starting level was 2.5 to 5.2 mmol/L
Very high risk	Below 1.8 mmol/L, and at least a 50% reduction if your starting level was 1.8 to 3.5 mmol/L

These are the 2018 South African targets. Guidelines differ and are updated over time, so ask your clinician which targets apply to you.

For people who already have cardiovascular disease, such as a past heart attack or stroke, the UK's NICE guideline (NG238) recommends aiming for an LDL of 2.0 mmol/L or less.

Guidelines set different numbers. HEART UK, for example, reports that NICE itself recognises its targets are higher than other national and international targets, because they are based on cost-effectiveness. Your clinic will use its own national guideline. What matters most is the target your prescriber sets for you.

Non-HDL cholesterol

Non-HDL is total cholesterol minus HDL. The NHS calls it "bad cholesterol". NICE prefers non-HDL to LDL in some situations because it does not need a fasting blood test.

Healthy adults: below 4 mmol/L (NHS).
After a heart attack or stroke: NICE NG238 aims for 2.6 mmol/L or less.
Preventing a first heart attack or stroke with medicine: NICE aims for more than a 40% reduction in non-HDL from your starting level.
South Africa: a 2019 laboratory summary of the 2018 guideline gives non-HDL targets of below 2.6 mmol/L at very high risk and below 3.3 mmol/L at high risk.

Triglycerides

Triglycerides are a type of fat in the blood. They rise after meals, so they are the result most affected by eating before the test. A common laboratory reference range, based on HEART UK, is below 1.7 mmol/L fasting.

One NHS laboratory, drawing on HEART UK and NICE NG238, uses these action levels:

Triglyceride result	What the laboratory advises
4.5 to 9.9 mmol/L	Repeat the test fasting, and optimise other heart risk factors
10 to 20 mmol/L	Urgent repeat fasting lipid profile within 5 to 14 days. Specialist advice if it stays above 10 mmol/L
Above 20 mmol/L	Urgent specialist review, unless it is explained by poorly controlled diabetes or alcohol use

Very high triglycerides matter for another reason. A 2024 review in Diabetes & Primary Care notes that the risk of acute pancreatitis rises significantly once levels exceed 10 to 20 mmol/L. The laboratory guidance above also points to poor blood sugar control and alcohol use as causes to look for.

If triglycerides are very high, the calculated LDL may not be reported at all. The same review explains that laboratories may withhold calculated LDL when triglycerides are above 4.5 mmol/L.

Do I need to fast before a cholesterol test?

Often not. The NHS says "it does not make much difference to these levels whether you have eaten before your test or not." NICE notes that a fasting sample is not required, which is one reason it uses non-HDL cholesterol.

There are exceptions. Triglycerides rise after a meal, and the calculated LDL can be underestimated in a non-fasting sample. The Diabetes & Primary Care review recommends a fasting sample at least for a first baseline test, and laboratories ask for a fasting repeat when triglycerides are high.

Follow the instructions your clinic or laboratory gives you. The American Heart Association also says you will be told if you need to fast.

Why your numbers do not tell the whole story

The NHS says your doctor uses your cholesterol levels along with other factors, such as your age, blood pressure and health conditions, to estimate your risk of cardiovascular disease. In the UK this is often a QRISK score, which estimates how likely you are to have a heart or circulation problem over the next 10 years.

The American Heart Association likewise says results are read "in context with your age, sex and family history", along with smoking, diabetes and high blood pressure.

This is why two people with the same result can be given different advice. For example, a 35-year-old non-smoker with normal blood pressure and an LDL of 3.4 mmol/L is in a very different position from a 60-year-old smoker with diabetes and the same LDL.

Blood pressure matters just as much. If you have not had it checked recently, read our guide to blood pressure readings.

For men, erection problems can be an early warning sign of heart disease, which we explain in erectile dysfunction and heart health.

The NHS also notes that results can be lower or higher than usual if you have been ill, are taking some medicines, or have recently had a baby. If your result is unexpected, ask whether a repeat test makes sense.

Familial hypercholesterolaemia: when it runs in the family

Some people have very high cholesterol because of an inherited condition called familial hypercholesterolaemia (FH). A 2019 Ampath summary of the South African guideline says population studies estimate heterozygous FH may affect as many as 1 in 200 to 1 in 250 people, and says genetic testing can be considered when total cholesterol is 7.5 mmol/L or higher.

Ask your doctor about FH if your result is at that level, or if very high cholesterol runs in your family. Because it is inherited, the same summary describes testing relatives of a person found to have it (cascade screening).

What to do next: step by step

Get a copy of your results. Ask for the actual numbers, not just "normal" or "high". If the report only shows total cholesterol, the NHS says you can ask whether you can get separate HDL and non-HDL results.
Check the units. Make sure you are comparing mmol/L with mmol/L.
Ask for your overall risk. Ask your doctor or nurse to work out your 10-year risk of heart attack or stroke, and what your personal target is.
Look at the rest of your health. Blood pressure, blood sugar, weight and smoking all change what your cholesterol result means. If you have been told you have prediabetes, see our guide to what your A1C result means.
Make the changes that lower cholesterol. See the list below.
If you are offered a statin, ask questions. Ask why it is recommended for you, what target you are aiming for, and when your next test will be. Do not stop a prescribed cholesterol medicine without speaking to your prescriber.
Book your follow-up test. Treatment targets are checked by repeating the test.

Everyday changes that help

The NHS recommends:

Eating more oily fish such as mackerel and salmon, olive or rapeseed oil, brown rice, wholegrain bread and wholewheat pasta, nuts and seeds, and fruit and vegetables.
Eating less fatty meat, meat pies and sausages, butter, lard and ghee, cream and cheese, cakes and biscuits, and food that contains coconut oil or palm oil.
Exercising for at least 150 minutes of moderate-intensity activity, or 75 minutes of vigorous activity, a week.
Stopping smoking. The NHS says smoking can raise your cholesterol and makes heart attacks, strokes and cancer more likely.
Keeping alcohol down. The NHS advises not regularly drinking more than 14 units a week, spreading drinking over 3 or more days, and having several drink-free days each week.

If palm oil or fatty cuts of meat are regular ingredients in your cooking, swapping the oil and choosing leaner cuts follows this NHS advice directly. If you also have diabetes or prediabetes, our type 2 diabetes food list covers African staples such as sadza and ugali.

Questions to ask your doctor, nurse or pharmacist

What is my 10-year risk of a heart attack or stroke?
Which of my numbers is the one we are trying to change, and what is my target?
Was my test fasting, and do I need a repeat?
Could my high cholesterol run in the family?
If I start a statin, when will we recheck my levels?

Frequently asked questions

What is a normal cholesterol level?

For healthy adults, the NHS gives total cholesterol below 5 mmol/L, non-HDL below 4 mmol/L, and HDL above 1.0 mmol/L for men or above 1.2 mmol/L for women. Targets are lower if you are at high risk or already have heart disease.

What is a good LDL cholesterol level?

It depends on your risk. The South African guideline targets LDL below 3 mmol/L at low or moderate risk, below 2.5 mmol/L at high risk, and below 1.8 mmol/L at very high risk. NICE aims for 2.0 mmol/L or less after a heart attack or stroke.

What is a good HDL cholesterol level?

HDL is called "good" cholesterol, and the NHS sets a healthy level as above 1.0 mmol/L for men and above 1.2 mmol/L for women. Your doctor reads it together with your other results and risk factors, such as age, blood pressure and health conditions, rather than on its own.

Do I need to fast for a cholesterol test?

Usually not. The NHS says eating beforehand does not make much difference to cholesterol levels. Triglycerides are more affected, so you may be asked for a fasting sample for a first test or if your triglycerides were high.

What does non-HDL cholesterol mean?

It is your total cholesterol minus your HDL, and the NHS calls it "bad cholesterol". The NHS healthy level is below 4 mmol/L for healthy adults.

What triglyceride level is dangerous?

A common reference range is below 1.7 mmol/L fasting. Levels of 10 mmol/L or more need an urgent repeat test and specialist advice if they stay high. Above 20 mmol/L, NHS laboratory guidance based on NICE advises urgent specialist review, unless it is explained by poorly controlled diabetes or alcohol use. A 2024 review notes that the risk of acute pancreatitis rises significantly once levels exceed 10 to 20 mmol/L.

This article is general information and does not replace advice from your own doctor or pharmacist. Please do not start, stop or change any medicine without speaking to them first.

Sources

NHS. Cholesterol levels. Last reviewed 13 March 2026.
NHS. How to lower your cholesterol.
National Institute for Health and Care Excellence. Cardiovascular disease: risk assessment and reduction, including lipid modification (NG238): frequently asked questions.
HEART UK. Response to NICE guidance, December 2023.
SA Heart and LASSA. South African dyslipidaemia guideline consensus statement: 2018 update. S Afr Med J. 2018.
Ampath. CHAT 61: Lipid update, changes to South African dyslipidaemia guidelines 2018. October 2019.
Davies C, Wainwright P. Q&A: Lipid management, part 1: measuring lipids and lipid targets. Diabetes & Primary Care. 2024;26(3):85.
NHS laboratory services. Triglycerides (serum).
American Heart Association. How to get your cholesterol tested.