High cholesterol - symptoms, causes and levels

Cholesterol explained

What is high cholesterol?

Cholesterol is a fatty substance in your blood that’s produced naturally in your liver. Having some cholesterol is important because the cells in your body use cholesterol to keep them healthy.

But if you have too much cholesterol in your blood, it’s called high cholesterol. Having too much cholesterol in your blood can narrow your arteries and cause fatty material to build-up (atherosclerosis). This can increase your risk of having a heart attack or stroke.

You may hear high cholesterol being called hypercholesteroalemia or hyperlipidemia. Your doctor may call it lipid dysregulation or say you have an abnormal lipid profile after a blood test.

What is ‘good’ and ‘bad’ cholesterol?

Cholesterol is carried around your body by proteins in your blood. When cholesterol and proteins combine, they’re called lipoproteins.

There are two main types of lipoproteins, you may hear them being called good and bad cholesterol.

• High-density lipoproteins (HDL) or ‘good’ cholesterol takes cholesterol that you do not need back to your liver. The liver breaks it down and it’s passed out of your body. It helps get rid of bad cholesterol from your blood.
• Non-high density lipoproteins (non-HDL) or ‘bad’ cholesterol takes cholesterol from your liver to cells around your body. If you have too much it gets stuck to the walls of your arteries and can lead to a heart attack or stroke. This is mostly made up of LDL cholesterol, which is a type of bad cholesterol.

What are triglycerides?

Our blood also contains a fat called triglycerides. Triglycerides help to give you energy and look after your health. But if you have too much in your blood your arteries can become narrow. This can increase your risk of a heart attack or stroke.

Living with excess weight, eating food that’s high in saturated fat and sugar, and drinking too much alcohol can cause high triglyceride levels. High triglyceride levels can also be caused by inherited or genetic conditions and other health conditions.

Your doctor can tell you if your triglyceride levels are too high when they check your cholesterol.

Find out more about triglycerides levels and how to reduce them.

What is dietary cholesterol?

Some foods naturally contain cholesterol, such as eggs, liver, kidney and shellfish, like prawns. This is called dietary cholesterol.

For most people, dietary cholesterol does not have much effect on your cholesterol levels. You can eat foods containing cholesterol as part of a healthy diet.

Causes

What causes high cholesterol?

Anyone can get high cholesterol. It can be caused by lots of different things. Some you can influence and others you cannot.

Lifestyle factors you can influence

• your diet and eating too much saturated fat
• exercise and not being active enough
• smoking
• living with excess weight, especially round your middle.

Find lots of simple swaps and easy tips to lower your cholesterol in our Understanding high cholesterol booklet.

Age, sex and other conditions

• Age – getting older can increase your cholesterol levels.
• Ethnicity – your ethnicity may increase your risk of high cholesterol. 
• Biological sex – being born male means you have an increased risk of high cholesterol from a younger age.
• Menopause – during and after the menopause, your risk of high cholesterol goes up.
• Family history – if you have a family member who had a heart attack or stroke before the age of 60 that was caused by a blocked or narrowed blood vessel, it can increase your risk of having high cholesterol.
• Genetics – some causes of high cholesterol are passed down through families. This includes familial hypercholesterolaemia (FH) and high LP(a) levels.

If you’re transgender you may have a higher risk of heart disease and high cholesterol. Speak to your doctor to understand your risk of high cholesterol. 

Other causes of high cholesterol

• kidney disease
• liver disease
• type 2 diabetes
• having an underactive thyroid (hypothyroidism)
• growth hormone deficiency. 

Read more about the causes of high cholesterol on Heart UK’s website.

Symptoms

What are the symptoms of high cholesterol?

Most people with high cholesterol have no symptoms.

It’s a hidden risk factor, meaning you can have it without knowing. That’s why it’s important to get your cholesterol levels checked by having a blood test.

If you have familial hypercholesterolaemia (FH) you may have visible signs of high cholesterol.

Cholesterol levels

How do I get my cholesterol levels checked?

Your cholesterol is measured using a blood test. A cholesterol blood test is sometimes called a lipid profile because it looks at different fats in your blood.

You can get your cholesterol checked at:

• your GP practice
• some pharmacies, using a finger-prick test.

Adults in England should be offered a free NHS health check when they turn 40. The rest of the UK may also have similar schemes. Ask your GP or pharmacist for more information.

What are the normal levels of cholesterol?

A cholesterol blood test (lipid profile) will measure your:

• levels of good cholesterol (HDL)
• levels of bad cholesterol (non-HDL)
• cholesterol ratio
• triglycerides
• total cholesterol.

Your GP may also ask for your LDL levels to be checked.

What does primary and secondary prevention mean?

Your doctor may use the words primary or secondary prevention.

Primary prevention is managing your cholesterol and heart health to prevent you having a heart attack or stroke in the future.

Secondary prevention is managing your cholesterol and heart health after you’ve had a heart attack or stroke, to prevent you having another one.

If you’ve had a heart attack or a stroke your recommended levels of cholesterol and triglycerides may be lower.

Talk to your doctor about what your cholesterol levels should be based on your individual health and any risk factors.

Managing high cholesterol

What changes can I make to lower my cholesterol?

There are lots of things you can do to help lower your cholesterol:

• Cut down the amount of saturated fat in your food. For example, you could swap butter for olive spread, or meat for fish. You could also make sure any food you buy is labelled green or orange for saturated fat instead of red.
• Try to be more active. For example, you could commit to walking every day at lunchtime, try a new hobby or swap a short drive for a walk or cycle.
• Reduce the amount of alcohol you drink each week. For example, you could swap one drink for a non-alcoholic version or swap a pint for a half pint of beer.
• Get support from your local pharmacy or GP to reduce and eventually stop smoking.

Find heart-healthy recipes to cook. You can also find lots of easy tips to help you lower your cholesterol in our booklet Understanding high cholesterol.

Which medicines help lower cholesterol?

Your doctor may also recommend medicine to help lower your cholesterol. Medicines can also help reduce your risk of a heart attack or stroke.

Statins are the most common medicine used to lower cholesterol. Sometimes other medicines can be prescribed, but this is usually by a specialist. Speak to your doctor if you have questions about medicines.

You will usually need to make healthy lifestyle choices as well as taking medicine to lower your cholesterol.

I have high cholesterol - how often should it be checked?

Your GP should invite you for a blood test every year to check your levels and how you’re getting on with any medicines or lifestyle changes

Speak to your doctor if you have any questions about your cholesterol.

Your top cholesterol questions

• How do I lower my cholesterol?
• How do statins lower my cholesterol and are there alternatives?
• Easy tips for lowering your cholesterol
• 5 foods to lower your cholesterol
• Foods to avoid if you have high cholesterol
• Exercises to lower your cholesterol

You can also explore our managing cholesterol hub for support to lower your cholesterol levels.

Get support

If you have high cholesterol, it's important to know you're not alone.

• Our cardiac nurses can help answer your questions on high cholesterol and statins. Call, email or live chat with them on our Heart Helpline.
• Sign up to Heart Matters for healthy recipes, new activity ideas, and expert tips for managing your health.
• Find information and support from Heart UK, the cholesterol charity.

Listen to this page or read it in another language