A blood test that measures cholesterol and other blood fats to help assess cardiovascular risk.
Cardiac investigation
Cholesterol testing (lipid profile)
What this test is and when it helps
A cholesterol test, usually called a lipid profile, is a blood test that measures the fats carried in your blood. It is used to estimate cardiovascular risk and to guide decisions about lifestyle and treatment.
It may be recommended as part of a health check, because of a family history of early heart disease or high cholesterol, in diabetes, high blood pressure or kidney disease, after a heart attack or stroke, or to see how treatment is working. High cholesterol does not cause symptoms, so a blood test is the only way to find it.
Dr Mark Cassar reviews and interprets the results alongside your overall cardiovascular risk, family history and any existing heart disease.
For selected patients, Lp(a), ApoB and other advanced cholesterol tests add detail, but they are not part of a standard lipid profile.
What a lipid profile measures
Total cholesterol
All the cholesterol in the blood. It is a rough summary and is incomplete on its own.
LDL cholesterol
The cholesterol carried in low-density lipoprotein particles, the main form that builds up in artery walls. It is often calculated by the laboratory rather than measured directly.
HDL cholesterol
The cholesterol carried in high-density lipoprotein particles. A higher level is generally linked with lower risk, but it does not cancel out a raised LDL.
Non-HDL cholesterol
Total cholesterol minus HDL, which captures all the cholesterol in potentially harmful particles.
Triglycerides
Another type of blood fat, raised by alcohol, excess weight and diabetes, and rising after meals.
Important clinical distinctions
A number is not a diagnosis
The same cholesterol result means different things in different people. Interpretation depends on age, blood pressure, smoking, diabetes, family history and whether there is existing heart or artery disease.
Reference values, thresholds and targets
General reference values, the level at which treatment is considered, and a personal treatment target are three separate things. None is decided by one number alone.
What happens during the test and how results are interpreted
A blood sample is usually taken from a vein in the arm and sent to a laboratory. Most people do not need to fast, but follow any instruction you are given with the request. Finger-prick tests give a quick estimate and are not always a full lipid profile.
Results are interpreted as a whole. A result may be repeated if it is unexpected, if triglycerides are very high, or after treatment is started or changed. Very high cholesterol, or a strong family history, can raise suspicion of familial hypercholesterolaemia, an inherited condition, but it is not diagnosed from one result.
A cholesterol test shows risk factors, not the arteries themselves. A good result does not exclude coronary artery disease, and a raised result does not show that arteries are already narrowed.
When another test may be needed
Advanced lipid tests
Lp(a) and ApoB can help in selected situations, such as a strong family history.
Blood tests for other causes
Thyroid, liver, kidney and blood sugar tests look for conditions that can raise cholesterol.
Cardiac CT
Can show whether plaque or narrowing is present in the coronary arteries, which a blood test cannot.
Frequently asked questions
Do I need to fast?
Usually not. Follow any specific instruction you are given when the test is requested.
Is a high HDL a reason not to worry about a high LDL?
No. A higher HDL is encouraging, but it does not remove the risk from a raised LDL or other risk factors.
Why is my LDL not reported?
Laboratories often calculate LDL, and the calculation can be unreliable when triglycerides are high. Non-HDL cholesterol can then be used instead.
Does a normal cholesterol mean my arteries are healthy?
Not necessarily. Cholesterol is one risk factor among several, and the test does not show the arteries themselves.
Should I stop my cholesterol medicine if my result is good?
No. A good result may be because the treatment is working. Speak to the person who prescribed it before changing anything.
Discussing whether cholesterol testing is appropriate
Dr Mark Cassar can review your risk factors, family history and previous results, and arrange cholesterol testing where clinically appropriate. The page on high cholesterol explains assessment and treatment.
Or call 020 3198 9826 or email medicalsecretary@drcassar.co.uk
Not an emergency service. Call 999 for a medical emergency. Do not wait for a private appointment. Medical information disclaimer.