Why do you need to get your cholesterol levels checked?

Find out why keeping an eye on your cholesterol is so important for your health. 

What is cholesterol?

Cholesterol is a fatty substance mostly made by the liver that’s found naturally circulating in the blood. Some cholesterol comes from the food you eat too.

Your body needs cholesterol to work properly. It’s used by every cell, helps make vitamin D and some hormones, and is a component of bile, a fluid your liver makes to help with digestion.

However, too much of certain types of cholesterol can be bad for heart health as it increases the risk of you having a heart attack or stroke.  

Why does high cholesterol increase the risk of heart attack and stroke? 

Too much ‘bad’ cholesterol in your blood can cause fatty material (plaques) to build up in the walls of your arteries – a process called atherosclerosis. 

If a piece of this fatty material breaks off, a blood clot can form, which may block blood vessels called arteries that carry blood to your heart and brain. 

If this happens in an artery supplying your heart it can cause a heart attack. And if it happens in an artery supplying your brain it can cause a stroke.

The higher your cholesterol, the higher your risk of both a heart attack and stroke.  

But you cannot tell how high your cholesterol is without a blood test, which is why you need to have one.

When will I have a cholesterol test? 

You may have a blood test called a ‘lipid profile’ to check your cholesterol as part of an NHS Health Check in England. 

Your GP may also check your cholesterol levels if they’re worried you may have high levels. 

If you have had a heart attack or stroke or have coronary heart disease, your doctor should be regularly checking your blood cholesterol levels.  

What will I be tested for?

Your test will tell you the total amount of cholesterol in your blood and will also measure two main types of cholesterol:

• Non-HDL (high-density lipoprotein) or ‘bad’ cholesterol, which can build up in your arteries. 
• HDL or ‘good’ cholesterol, which carries excess cholesterol back to your liver. 

You may also be tested for another kind of fat in your blood called triglycerides, which have been shown to raise the risk of heart and circulatory disease too.

If your doctor thinks you need treatment, you may also be tested for LDL (low-density lipoprotein) cholesterol, which is a form of non-HDL or ‘bad’ cholesterol.  

What are normal cholesterol levels?

Cholesterol levels vary from person to person, but in general the lower the non-HDL and LDL cholesterol and the higher the HDL cholesterol, the better.

Your blood cholesterol is measured in mmol/L, which stands for millimoles per litre. 

The recommended healthy levels are:

• Non-HDL cholesterol (‘bad’ cholesterol) – 4mmol/L or below.
• LDL cholesterol (‘bad’ cholesterol) - below 3mmol/L or below.
• HDL cholesterol (‘good’ cholesterol) – 1mmol/L or above for men and 1.2mmol/L or above for women.
• Total cholesterol - 5mmol/L or below.
• Total cholesterol to HDL ratio - 6 or below.

However, these levels are just a guide. Talk to your doctor about your results and what levels you should aim for.

If you have had a heart attack or stroke, your risk of having another one is higher, so your recommended healthy levels will be lower:

• Non-HDL cholesterol - 2.6mmol/L or below.
• LDL cholesterol - 2.0mmol/L or below.
• Total cholesterol - 4.0mmol/L or below.

When should I be worried?

If your doctor says you have ‘high cholesterol’ they may be referring to your ‘bad cholesterol’ levels, which are known to increase the risk of heart attack and stroke.

Your doctor will recommend lifestyle changes, such as a diet low in saturated fats and regular exercise, to help lower your levels.

They will also assess other risk factors for heart disease and will prescribe medicines to help reduce your cholesterol levels if they think they’re needed.

However, if you have familial hypercholesterolemia (a genetic condition which can lead to high cholesterol) you will need to take medicines to manage your cholesterol levels. Your doctors will discuss this with you. 

How will my doctor decide if I need medicines? 

Your doctor will look at all your risk factors for heart attack and stroke, not just your cholesterol levels, to work out if you need medicines to lower your cholesterol.

They will perform a ‘cardiovascular risk assessment’ to predict your risk of having a heart attack or stroke in the next 10 years.

They will likely use a computer programme called QRISK, so you may hear them talk about a ‘QRISK score’.

If the score suggests you have a 10 per cent or higher risk of heart attack or stroke, you will likely be prescribed medicines, usually a statin, to take as well as making lifestyle changes, to help lower your cholesterol.

You can also use the online Heart Age Tool, which was developed by British Heart Foundation with Public Health England and the NHS, to get an idea of how old your heart is and any steps you may want to take to improve it. This tool is more accurate if you already know your cholesterol levels.

If you’ve been diagnosed with coronary heart disease, taking statins has been proven to reduce your risk of having a heart attack or stroke, even if your cholesterol levels are in the healthy range.

Can I lower my cholesterol naturally?

Making healthy lifestyle changes can certainly help to bring your cholesterol levels down.

Eating lots of fruit and vegetables, whole grains (especially oats), and beans and lentils can help lower your cholesterol.

Losing excess weight, avoiding foods high in saturated fat, quitting smoking and being active can help too.

However, it’s important to understand that while these lifestyle measures can make a difference, you may still need to take medicine to lower your cholesterol as well.

If you’re concerned about taking statins or other medicines to lower cholesterol, speak about this with your doctor. 

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Updated 27 September 2024