Most people don’t know they have raised cholesterol. There are no clear symptoms. For some, the first sign might be a heart attack.
Excess blood cholesterol becomes stuck in the linings of an artery, eventually the artery narrows.
Cholesterol Tests - know your numbers
When to have your cholesterol tested
It’s important to understand who should have a cholesterol test and how often to repeat it:
- Every 5 years if you are between the ages of 40 and 75
- Every 12 months if you are on cholesterol lowering medication
- Any child of a parent with inherited high cholesterol (FH) - by the age of 10
- First degree relatives of a person with FH - on being told of the risk
The NHS will provide you with a free cholesterol test if you fall into any of the above groups, speak to your Doctor or Practice Nurse about arranging your cholesterol test.
What does a cholesterol test involve?
Cholesterol tests should only be performed by health care professionals and other agencies that have had the necessary training. It is important to take a blood sample safely and to operate and maintain the testing equipment properly. You should make sure that you are well hydrated before your test and have eaten normally unless otherwise advised by your doctor or health care professional.
- A venous sample is usually taken to perform a full lipid profile (to find out the levels of all blood fats). The health care professional takes a sample of blood from a vein, usually in the arm. The sample is then sent to a laboratory where it is analysed and the results are usually available within 48 hours. This test will provide you with your total cholesterol, HDL-cholesterol, non- HDL cholesterol and triglyceride concentrations. New guidelines by the National Institute for Health and Care Excellence (NICE) advise that there is now no need to fast before the test. However in certain circumstances, your health care professional may request a fasting test (no food for 10-14 hours) and they will inform you of the reason for this test.
- A capillary (pinprick) test care testing device. The test usually requires just a small drop of blood, usually taken from a finger. The blood is placed on a cassette or strip that is inserted into a calibrated device or meter. The result is available within a few minutes. This kind of test may be used for screening purposes but can also form part of an NHS Health Check and is non-fasting. This test is usually used to to find out the amount of total cholesterol and HDL-cholesterol in your blood.
What cholesterol results should you expect?
In order to understand the risk that cholesterol poses to your health it is important to know all your numbers: Your surgery may only tell you there is nothing to worry about or they may only give you your total cholesterol (TC) figure. Be sure to ask them for all the results they have and keep a note of them. As a minimum you should know your total cholesterol, non-HDL cholesterol and HDL-cholesterol (explained below). Don't worry if you get a high result as a diagnosis of high cholesterol cannot usually be made from the results of just one test. In the UK all cholesterol levels are measured in millimoles per litre (mmol/L) but in some countries they are measured in milligrams per decilitre (mg/dl). You can find out how to convert between these measures here.
- Total Cholesterol (TC) - this is the total amount of cholesterol in your blood. Ideally it should be 5 mmol/L* or less
- Non HDL-Cholesterol this is your total cholesterol minus your HDL-cholesterol (good cholesterol) and is the sum all the "bad" cholesterols added together (including LDL cholesterol) - ideally it should be 4mmol/L* or less
- LDL-Cholesterol (LDL-C) - this is the amount of LDL-cholesterol), ideally it should be 3 mmol/L* or less
- HDL-Cholesterol (HDL-C) - the amount of good cholesterol, ideally it should be over 1mmol/L* (men) and over 1.2mmol/L* (women).
- TC:HDL ratio This is the TC figure divided by the HDL-C figure. A ratio above 6 is considered high risk - the lower this figure is the better.
- Triglyceride (TG) this represent your body's ability to clear fat from the blood after a meal. Ideally it should be less than 2mmol/L* on a fasting sample)
** mmol/L stands for millimoles per litre
If you have existing heart disease or are at a higher risk of developing heart disease, it is likely that your doctor will advise you to reduce your cholesterol further. It is best to discuss this with your doctor when he or she reviews your treatment. Any target cholesterol levels your doctor suggests will depend on the cause of your high cholesterol, your age and any other risk factors you have.
Now you know your levels you can enter them into the HEART AGE tool to find out your heart age
For further information please see our fact sheets and web pages on:
Cholesterol and lipoproteins - includes further information on LDL and HDL
Can I test my own cholesterol at home?
Taking blood, and using point-of-care or instant testing kits to determine cholesterol and other blood fats is a skilled job. Your results can be affected by the way you perform the test and therefore the result you get may not be a true indication of your level or your risk. HEART UK recommend only having your cholesterol tested by a trained professional. We do not approve or endorse Home Cholesterol Testing Kits.