Cholesterol, high


Cholesterol, high


Cholesterol is a fatty substance known as a lipid and is vital for the normal functioning of the body. It is mainly made by the liver but can also be found in some foods.

Having an excessively high level of lipids in your blood (hyperlipidemia) can have an effect on your health. High cholesterol itself does not cause any symptoms, but it increases your risk of serious health conditions.


About cholesterol

Cholesterol is carried in your blood by proteins, and when the two combine they are called lipoproteins. There are harmful and protective lipoproteins known as LDL and HDL, or 'bad' and 'good' cholesterol.

Low-density lipoprotein (LDL): LDL carries cholesterol from your liver to the cells that need it. If there is too much cholesterol for the cells to use, it can build up in the artery walls, leading to disease of the arteries. For this reason, LDL cholesterol is known as "bad cholesterol".

High-density lipoprotein (HDL): HDL carries cholesterol away from the cells and back to the liver, where it is either broken down or passed out of the body as a waste product. For this reason, it is referred to as "good cholesterol" and higher levels are better.

The amount of cholesterol in the blood (both LDL and HDL) can be measured with a blood test. The recommended cholesterol levels in the blood vary between those with a higher or lower risk of developing arterial disease.


Why should I lower my cholesterol?

Evidence strongly indicates that high cholesterol can increase the risk of:

narrowing of the arteries (atherosclerosis) 

heart attack


mini-stroke (TIA)

This is because cholesterol can build up in the artery wall, restricting the flow of blood to your heart, brain and the rest of your body. It also increases the chance of a blood clot developing somewhere.

Your risk of coronary heart disease (when your heart's blood supply is blocked or disrupted) also rises as your blood's cholesterol level increases and this can cause pain in the front of the chest or arm (angina) during stress or physical activity.


What causes high cholesterol?

There are many factors that can increase your chance of having heart problems or stroke if you have high cholesterol, including the following:

an unhealthy diet: some foods already contain cholesterol (known as dietary cholesterol) but it is the amount of saturated fat in your diet which is more important

smoking: a chemical found in cigarettes called acrolein stops HDL transporting fatty deposits to the liver, leading to narrowing of the arteries (atherosclerosis)

having diabetes or high blood pressure (hypertension)

having a family history of stroke or heart disease

There is also an inherited condition known as familial hypercholesterolaemia (FH). This can cause high cholesterol even in someone who eats healthily.


When should I test my cholesterol levels?

Your GP may recommend that you have your blood cholesterol levels tested if you:

have been diagnosed with coronary heart disease, stroke or mini-stroke (TIA) or peripheral arterial disease (PAD)

have a family history of early cardiovascular disease

have a close family member who has a cholesterol-related condition

are overweight

have high blood pressure, diabetes or a health condition that can increase cholesterol levels


How can I lower my cholesterol levels?

The first step in reducing cholesterol is to maintain a healthy, balanced diet. It is important to keep your diet low in fatty food. Try to swap food containing saturated fat for fruit, vegetables and wholegrain cereals. This will also help to prevent high cholesterol from returning.

Other lifestyle changes can also make a big difference. It will help to lower your cholesterol if you:

do regular exercise – read tips on improving your health and fitness

quit smoking – read information about how to stop smoking

If these measures don't reduce your cholesterol and you continue to be at a high risk of heart disease, your GP may prescribe a cholesterol-lowering medication such as statins. Your GP will take into account the risk of any side effects from statins and the benefit of lowering your cholesterol must outweigh any risks.


Causes of high cholesterol 

Lots of different factors can contribute to high blood cholesterol, including diet, age, family history and ethnic group.




Your lifestyle can increase your risk of developing high blood cholesterol. This includes:

An unhealthy diet. Some foods, such as liver, kidneys and eggs, contain cholesterol (known as dietary cholesterol). However, this has little effect on blood cholesterol and it is the amount of saturated fat in your diet which is more important. Read more information about preventing high cholesterol.

Lack of exercise or physical activity.This can increase your level of "bad cholesterol" (low-density lipoprotein, or LDL). 

Obesity. If you are overweight, you are likely to have higher levels of LDL cholesterol and triglycerides, and a lower level of high-density lipoprotein (HDL).

Drinking excessive amounts of alcohol. Regularly drinking a lot of alcohol can increase your cholesterol and triglyceride levels.

Smoking. A chemical found in cigarettes called acrolein stops "good cholesterol" (HDL) from transporting fatty deposits to the liver, leading to narrowing of the arteries (atherosclerosis).


Underlying conditions

People with high blood pressure (hypertension) and diabetes often have high cholesterol. Some medical conditions can also cause raised levels of cholesterol. These include:

kidney disease

liver disease

an underactive thyroid gland

Treating the underlying condition can help to reduce cholesterol. 


Other factors

There are a number of factors associated with high cholesterol that cannot be changed. Doctors refer to these as fixed factors and they include:

Family history of early heart disease or stroke. You are more likely to have high cholesterol if you have a close male relative (father or brother) aged under 55 or a female relative (mother or sister) aged under 65 who has had coronary heart disease or stroke.

A family history of a cholesterol-related condition, for example if a close relative, such as a parent, brother or sister, has familial hypercholesterolaemia (see below).

Age. The older you are, the greater the likelihood of your arteries narrowing (atherosclerosis).

Ethnic group. People who are of Indian, Pakistani, Bangladeshi or Sri Lankan descent have an increased risk of high blood cholesterol.

If you have a fixed risk factor (or a number of fixed risk factors) it's even more important to look at your lifestyle and any underlying conditions that you may have.



Familial hypercholesterolaemia is the medical term for high cholesterol that runs in the family. It is not caused by an unhealthy lifestyle, but by genetics. About one in 500 people inherit the condition from a parent.

Cholesterol is not cleared properly from your bloodstream and living with higher levels of cholesterol produces early heart problems.



Triglycerides are another type of fatty substance in the blood. They are produced by the liver and are also found in dairy products, meat and cooking oils.

An increased risk of having a high triglyceride level may be due to:

being overweight

eating a diet high in fatty or sugary foods

drinking a large amount of alcohol

genetic factors


Diagnosing high cholesterol - getting a cholesterol test 

Blood cholesterol levels are measured with a simple blood test. This blood sample will be used to determine the amount of LDL (bad cholesterol), HDL (good cholesterol) and triglycerides (other fatty substances) in your blood.

You may be asked not to eat for 10-12 hours before the cholesterol test (usually including when you are asleep at night). This ensures that all food is completely digested and will not affect the outcome of the test.

Your GP or practice nurse can carry out the cholesterol test and will take a blood sample either using a needle and a syringe or by pricking your finger.



At the end of your assessment your healthcare professional will explain your results and will calculate whether you have a high, moderate or low risk of getting cardiovascular disease (heart disease or stroke) within the next 10 years.

However, this risk is not just based on your cholesterol reading – it also takes into account:

your BMI (body mass index), which measures your weight in relation to your height

treatable risk factors, such as high blood pressure (hypertension), diabetes and other medical conditions

your age, sex, family history and ethnicity

The ideal cholesterol levels for healthy adults and for those at high risk of cardiovascular disease are explained below.



Total cholesterol level

Blood cholesterol is measured in units called millimoles per litre of blood, often shortened to mmol/L.

The government recommends that total cholesterol levels should be:

5mmol/L or less for healthy adults

4mmol/L or less for those at high risk

In the UK in 2011, around 50% of adults had a cholesterol level above 5mmol/L. This figure has been improving steadily since the last measurement in 2003.

On average, men in England have a cholesterol level of 5mmol/L and women have a level of 5.1mmol/L.


Levels of LDL and HDL

The government recommends that levels of low-density lipoprotein (LDL) should be:

3mmol/L or less for healthy adults

2mmol/L or less for those at high risk

An ideal level of high-density lipoprotein (HDL) is above 1mmol/L. A lower level of HDL can increase your risk of heart disease.

Your ratio of total cholesterol to HDL may also be calculated. This is your total cholesterol level divided by your HDL level. Generally, this ratio should be below four, as a higher ratio increases your risk of heart disease.



Your doctor or nurse may also measure your level of triglycerides. Triglycerides are the fats you use for energy and come from the fatty foods you eat. You store what you do not use in the fatty tissues of your body. Excess triglycerides in the blood also increase heart problems.

Your ideal level of triglycerides should be less than 1.7mmol/l.


Who should be tested?

Your GP may recommend that you have your blood cholesterol levels tested if you:

have been diagnosed with coronary heart disease, stroke or mini-stroke (TIA) or peripheral arterial disease (PAD)

are over 40years old

have a family history of early cardiovascular disease (for example, if your father or brother developed heart disease or had a heart attack or stroke before the age of 55, or if your mother or sister had these conditions before the age of 65)

have a close family member who has a cholesterol-related condition, such as familial hypercholesterolaemia (inherited high cholesterol)

are overweight or obese

have high blood pressure or diabetes

have another medical condition such as a kidney condition, an underactive thyroid gland or an inflamed pancreas (pancreatitis). These conditions can cause increased levels of cholesterol or triglycerides


Treating high cholesterol 

If you've been diagnosed with high cholesterol, you will at first be advised to make changes to your diet and increase your level of exercise.

After a few months, if your cholesterol level has not dropped, you will usually be advised to take cholesterol-lowering medication.

Changing your diet, stopping smoking and doing more exercise will also help prevent high cholesterol developing. 



Eating a healthy diet that is low in saturated fats can reduce your level of LDL (bad cholesterol).

Try to avoid or cut down on the following foods, which are rich in saturated fat:

fatty cuts of meat and meat products, such as sausages and pies

butter, ghee and lard

cream, soured cream, creme fraiche and ice cream

cheese, particularly hard cheese

cakes and biscuits


coconut oil, coconut cream and palm oil


the average man should have no more than 30g saturated fat a day

the average woman should have no more than 20g saturated fat a day

To get an idea of how much saturated food you are consuming, take a look at the food labels of the foods you are eating.


Omega-3 fatty acids

Many experts believe that the fats found in avocados and oily fish such as mackerel, salmon and tuna are good for you.

These are known as omega-3 fatty acids and high doses can improve (lower) triglyceride levels in some patients. However, too much can contribute to obesity.

For those with a high triglyceride level, around two oily-fish based meals a week is thought to be beneficial.

However there is no evidence that taking omega-3 fatty acid supplements has the same benefit.

Cholesterol-lowering medication

There are several different types of cholesterol-lowering medication that work in different ways. Your GP can advise you about the most suitable type of treatment. Your GP may also prescribe medication to lower high blood pressure (hypertension) if it affects you.

The most commonly prescribed medications are outlined below.



Statins block the enzyme (a type of chemical) in your liver that helps make cholesterol. This leads to a reduction in your blood cholesterol level.

You will usually be started on the drug atorvastatin. Other statins include simvastatin and rosuvastatin.

When someone has side effects from using a statin, this is described as "intolerance" to it. Side effects of statins include muscle pain and stomach problems.

Statins will only be prescribed to people who continue to be at high risk of heart disease as you usually need to take statins for life. This is because cholesterol levels start to rise again once you stop taking them.



In some cases, a low daily dose of aspirin may be prescribed, depending on your age (children under 16 should not take aspirin) and other factors. Low-dose aspirin can prevent blood clots from forming.



Niacin is a B vitamin found in foods and multivitamin supplements. In high doses (available by prescription), niacin lowers triglycerides and raises HDL. Niacin can be offered to people with a high triglyceride level.

High doses of niacin can cause flushing (when your skin turns red), but more recent medications significantly reduce this side effect. Avoiding spicy foods also helps to reduce flushing.

Niacin is not used in people with current indigestion, stomach ache, stomach ulcers, or those at risk of developing these symptoms.

You may also be advised to have periodic blood tests to ensure your liver is functioning well.


Other medications

Ezetimibe is a medication that blocks the absorption of cholesterol from food and bile juices in your intestines into your blood. It is generally not as effective as statins, but is less likely to cause side effects.

You can take ezetimibe at the same time as your usual statin if your cholesterol levels are not low enough with the statin alone. The side effects of this combination are generally the same as those of the statin alone (muscle pain and stomach problems).

You can take ezetimibe by itself if you are unable to take a statin. This may be because you have another medical condition or you take medication that interferes with how the statin works, or because you experience side effects from statins. Ezetimibe taken on its own rarely causes side effects.


Preventing high cholesterol 

You can help to lower your cholesterol by eating a healthy, balanced diet that is low in saturated fat, doing regular exercise, stopping smoking and cutting down on alcohol.



Eating an unhealthy diet that is high in fat will cause fatty plaques to build up in your arteries. This is because fatty foods contain cholesterol.

There are also two types of fat: saturated and unsaturated. Avoid foods containing saturated fats because they will increase the levels of bad cholesterol in your blood.

Foods high in saturated fat include:

meat pies

sausages and fatty cuts of meat


ghee (a type of butter often used in Indian cooking)



hard cheese

cakes and biscuits

food that contains coconut or palm oil

However, it is not healthy to completely cut out all types of fat from your diet. It is important to replace saturated fats with unsaturated fats, as they have been shown to increase levels of good cholesterol and help reduce any blockage in your arteries.

Foods that are high in unsaturated fat include:

oily fish (mackerel, salmon, tuna)


nuts and seeds

sunflower, rapeseed and olive oil

Eating a low-fat diet including lots of fibre, such as wholegrain rice, bread and pasta, and plenty of fruit and vegetables, has also been proven to help lower cholesterol. Fruit and vegetables are full of vitamins, minerals and fibre and help keep your body in good condition. Aim to eat five 80g portions of fruit and vegetables every day.



A chemical found in cigarettes called acrolein stops "good cholesterol" (HDL) from transporting fatty deposits to the liver, leading to high cholesterol and narrowing of the arteries (atherosclerosis). This means that smoking is a major risk factor for both heart attacks and strokes.

If you are committed to giving up smoking but don't want to be referred to a stop smoking service, your GP should be able to prescribe medical treatment to help with any withdrawal symptoms that you may experience after giving up.



Being active and taking regular exercise will help to increase the levels of "good cholesterol" (HDL) in your body by stimulating the body to move fatty deposits to the liver so they can be broken down.

It will also help to lower your blood pressure by keeping your heart and blood vessels in good condition and helping you to lose weight. Being overweight can increase the amount of "bad cholesterol" (LDL) in your blood.

Doing 150 minutes of moderate-intensity exercise every week is recommended to help lower your cholesterol. Find out more about getting more active and achieving your recommended activity levels.

Walking, swimming and cycling are all good examples of this kind of exercise. Find out more about walking for health, swimming for fitness and the benefits of cycling.

Cholesterol, high