At a Glance
Why Get Tested?
To assess your risk of developing cardiovascular disease (CVD); to monitor treatment
When to Get Tested?
Aged 40 as part of a routine cardiovascular health check, or if you are already thought to be at risk of cardiovascular disease for another reason, or to monitor your response to lipid-modifying treatments.
A blood sample is obtained by inserting a needle into a vein in your arm, or occasionally from a fingerprick.
Test Preparation Needed?
Typically, fasting for 12 hours before having your blood taken is required; only water is permitted. Follow any instructions you are given.
The Test Sample
What is being tested?
Lipids are a group of fats and fat-like substances that are important constituents of cells and sources of energy. They are necessary for life, but if present in excess they can lead to health problems – in particular cardiovascular disease. A lipid profile measures the level of specific lipids in the blood.
Two types of lipids, cholesterol and triglycerides, are transported in the blood by particles called “lipoproteins”. Each particle contains a combination of protein, cholesterol, triglyceride, and phospholipid molecules. Lipoprotein particles are classified according to their density into high-density lipoproteins (HDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), and very low-density lipoproteins (VLDL). Not all of these are measured as part of a routine lipid profile.
A lipid profile typically includes:
- Total cholesterol —this test measures all of the cholesterol in all the lipoprotein particles.
- High-density lipoprotein cholesterol (HDL-C) — measures the cholesterol in HDL particles; often called "good cholesterol" because it removes excess cholesterol and carries it to the liver for removal.
- Low-density lipoprotein cholesterol (LDL-C) — calculates the cholesterol in LDL particles; often called "bad cholesterol" because it deposits excess cholesterol in walls of blood vessels, which can contribute to atherosclerosis (“furring up of the arteries”). Usually, the amount of LDL cholesterol (LDL-C) is calculated using the results of total cholesterol, HDL-C, and triglycerides.
- Triglycerides — measures all the triglycerides in all the lipoprotein particles; most is in the very low-density lipoproteins (VLDL).
Some other information may be reported as part of the lipid profile. These parameters are calculated from the results of the tests identified above.
- Non-HDL-C — calculated from total cholesterol minus HDL-C.
- Cholesterol/HDL ratio — calculated ratio of total cholesterol to HDL-C.
How is the sample collected for testing?
Testing for your lipid profile requires a blood sample. Most often, the blood sample is collected by venepuncture (using a needle to collect blood from a vein in the arm). Occasionally a fingerprick test can be used, although this is not commonly available in GP practices or hospitals in the UK.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
Typically, fasting for 12 hours before having the blood sample drawn is required; only water is permitted. Your doctor might recommend a slightly shorter or longer fast. Follow any instructions you are given.
Ask a Laboratory Scientist
NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.