Learn about high cholesterol
High cholesterol or an unhealthy balance of blood fats can lead to health problems. Learn about the causes and how it can affect your body.
Getting a cholesterol test
More people than ever are using home sampling kits to measure their cholesterol. While we do not recommend this approach, if you do decide to take a test or sample at home, there are some simple measures you can follow to take your sample safely and improve the accuracy of the results. We recommend getting a test from a health professional wherever possible – read more below.
Why get a cholesterol check?
We recommend that all adults should get a cholesterol check – no matter what your age or how healthy you feel.
High cholesterol doesn't usually have any signs or symptoms, so the only way to know your cholesterol levels is to get a check.
It's possible to have raised cholesterol even if you're young, fit, and feel healthy – because your cholesterol levels depend on your genes as well as your lifestyle.
A cholesterol check involves a simple blood test. Your doctor should also check your levels of another fat called triglycerides, as these also affect your heart health.
High cholesterol can lead to heart attacks and strokes. A cholesterol test can be used along with other simple tests to give a good idea of your heart health and if you're at risk of health problems. These include a blood pressure test and finding out your BMI and waist measurement. The results will show you if you need to make any lifestyle changes or need treatment.
What does a cholesterol check involve?
You can have your cholesterol tested using a simple blood test. This is often a finger prick test. It’s quick, you only feel a small pinch, and the results can be checked there and then. Or, you might have a small blood sample taken from your arm using a needle and syringe, which will be sent off for testing.
You can eat and drink normally before the test unless your doctor asks you not to. If you have a sample taken with a needle and syringe, you might be asked not to eat for 10-12 hours beforehand, usually overnight.
The test should include the amounts of the different types of cholesterol and triglycerides.
What do the results of a cholesterol test mean?
When you have a cholesterol test, it is really important that your healthcare professional explains the results to you, to prevent unnecessary worry and confusion about the results. The results will include different types of cholesterol.
Ask for a print out of your results if you are not able to speak to your GP, nurse or pharmacist.
Total cholesterol
This is sometimes written as 'serum cholesterol' or 'TC' and refers to the overall level of cholesterol. But it’s not just the total cholesterol that’s important.
Non-HDL cholesterol
Your non-HDL cholesterol is your total cholesterol minus your HDL cholesterol. It’s the LDL and all the other 'bad' cholesterol added together, and ideally should be as low as possible.
HDL cholesterol
Your HDL cholesterol (high density lipoprotein, or 'good' cholesterol) helps clear the cholesterol out of your arteries, while your LDL cholesterol (low density lipoprotein, or 'bad' cholesterol) can clog them up. So your HDL cholesterol should be above 1mmol/L in men and above 1.2mmol/L in women, ideally around 1.4mmol/L. Currently our specialists believe that levels above this may not provide additional protection. You can read more about high levels of HDL here.
TC:HDL ratio
You might be given a ratio of HDL compared to the total cholesterol, written as TC:HDL ratio. You can work it out from your HDL and total cholesterol numbers. This should be as low as possible. Above 6 is considered high.
Interpreting your results
Your cholesterol results should be interpreted in relation to any other risk factors you may have (these are things which can lead to heart problems such as high blood pressure, being overweight or smoking) and any other health conditions (such as diabetes). Because of other risk factors or medical conditions, your doctor may recommend lowering your cholesterol level.
What is a healthy cholesterol level?
Sometimes you might be given your total cholesterol only. If this happens, ask for a break-down of the numbers. It’s possible to have a healthy total cholesterol level but an unhealthy ratio of total cholesterol to HDL.
As a minimum, you should be given the total cholesterol (TC) and HDL numbers, then you can work out your cholesterol ratio.
The figures in this table are a general guide for ideal cholesterol and triglyceride levels for healthy adults in the UK. If you have conditions such as heart disease or diabetes, your target levels may be lower. Your doctor will be able to tell you what your individual targets should be.
In the UK, your results will be in mmol/L, but elsewhere your results may be in mg/dL.
| mmol/L | mg/dL | |
| Total (serum) cholesterol | below 5.0 | below 193 |
| Non-HDL cholesterol | below 4.0 | below 155 |
| LDL cholesterol | below 3.0 | below 116 |
|
HDL cholesterol High levels of HDL do not offer extra protection. Read more here. |
above 1.0 for a man above 1.2 for a woman |
above 39 for a man above 46 for a woman |
| TC:HDL ratio | Above 6 is considered high risk - the lower this figure is the better | Above 6 is considered high risk - the lower this figure is the better |
If you have high cholesterol or triglycerides, or an unhealthy balance of blood fats, you and your doctor will probably want to bring these levels down to a healthy level, with healthy lifestyle changes and sometimes treatments.
Triglycerides are another type of blood fat and your triglyceride levels can tell you more about your health. If your triglycerides are high, it can mean you’re at risk of heart disease, liver disease and diabetes.
You might have your triglycerides tested when you have your cholesterol tested. People with high triglyceride levels often have a low HDL level, which is an unhealthy combination.
As a general rule, these are the ideal triglyceride levels for healthy adults:
| Fasting triglyceride | below 1.7mmol/L | below 150mg/dL |
| Non-fasting triglyceride | below 2.3mmol/L | below 204mg/dL |
Fasting triglycerides are where you fast for a period of time before your blood test, usually 10-14 hours.
Learn more about triglycerides and what can raise them.
Cholesterol levels for men and women
HDL levels differ for men and women
Women naturally have higher HDL cholesterol (good cholesterol) levels than men. This is due to differences in the genes.
Women should aim for an HDL cholesterol level above 1.2mmol/L while men should aim for above 1mmol/L. Find out what your other cholesterol levels should be.
Cholesterol levels can rise during pregnancy
During pregnancy, both cholesterol and triglyceride levels can significantly rise. At HEART UK, we don't recommend getting a cholesterol test during pregnancy because your results wont be accurate. Our advice is to wait until at least three months after your baby is born to get a cholesterol test. This means you don't need to worry unnecessarily.
Cholesterol levels rise during the menopause
Women may also find their cholesterol levels rise during the menopause.
Converting from mmol/l to mg/dl
In the UK, cholesterol levels are measured in millimoles per litre (mmol/l). If you have your cholesterol tested in Europe or USA, they will be measured in milligrams per deciliter (mg/dl). Here’s how to convert from one to the other.
To convert cholesterol levels:
Cholesterol mg/dl = mmol/l x 38.6
Cholesterol mmol/l = mg/dl ÷ 38.6
To convert triglyceride levels:
Triglyceride mg/dl = mmol/l x 88.5
Triglyceride mmol/l = mg/dl ÷ 88.5
Where can I get a test?
There are three main ways you can get a test.
- Visit your pharmacist.
- Visit your GP.
- Get an NHS Health Check.
Can I test my own cholesterol at home?
It’s better to have your cholesterol tested by a professional than to use a home cholesterol test. Taking blood and measuring cholesterol levels is a skilled job, and your results will be affected by the way you do the test. Going to a health professional means you will get an accurate reading.
You can read more about testing at home here.
When should I have a cholesterol check?
We believe all adults should know their cholesterol numbers, no matter what their age. Even if you haven’t been invited for a cholesterol check it’s a good idea to get one anyway, as it’s the only way to know your cholesterol numbers.
You should also be offered a free cholesterol test by the NHS if any of the following apply to you.
-
You are aged 40-74
Your GP should invite you for an NHS health check once every five years from the age of 40 to 74. The NHS health check is designed to spot the early signs of heart disease, stroke, kidney disease, diabetes and dementia. You’ll be weighed and measured, have a cholesterol check and a blood pressure check, and you’ll be asked some simple questions about your health. -
You are at high risk of heart disease
Your GP or practice nurse might also offer you a cholesterol test if you are more likely to develop heart disease. For example, if other people in your family have had it, you smoke, you’re overweight, or you have high blood pressure, diabetes or certain other health problems.
-
You have been diagnosed with heart disease
Or other related illnesses such as stroke, mini stroke (TIA) or peripheral arterial disease (PAD). -
You are taking medicines to lower your cholesterol
You should be offered a test every year. -
You have a close relative with familial hypercholesterolemia
If your mother, father, brother, sister or child has inherited high cholesterol, you should be offered a test when you find out. This type of high cholesterol runs in families.
Children of parents with familial hypercholesterolemia should be given a cholesterol check by the age of 10.
When should I not have a cholesterol test?
As measurements taken during pregnancy cannot give an accurate picture of a woman’s usual cholesterol levels, cholesterol measurements are not helpful during pregnancy. Find out why.
Using the Heart Age Tool
Once you have your cholesterol results you can work out your risk of developing heart disease over the next 10 years using the NHS Heart Age Tool. You can get a more accurate measurement if you know what your blood pressure is and it will tell you your heart age compared to your real age.
The NHS wants to prioritise health checks in those aged between 40-74 but this does not mean other age groups are excluded. People from the age of 25 up to age 84 can still use the heart age tool to work out their risk of heart disease.