This factsheet is for people who have high cholesterol, or who would like information about it.

Cholesterol is a type of fat (lipid) made by the body. It's essential for good health and is found in every cell in the body. However, having a high level of certain types of cholesterol in the blood (hypercholesterolaemia) can increase the risk of heart disease and stroke.

 

What cholesterol is and what blood tests for high cholesterol show
About high cholesterol

Symptoms of high cholesterol

Complications of high cholesterol
Causes of high cholesterol
Diagnosis of high cholesterol
Treatment of high cholesterol
Prevention of high cholesterol

What cholesterol is and what blood tests for high cholesterol show

 

HAbout high cholesterol

Having high cholesterol affects your heart and blood vessels and increases your risk of developing cardiovascular disease (CVD). High cholesterol causes fatty deposits (known as plaques) to build up inside your blood vessels.
In time, the blood vessels supplying your heart may become so narrow that they can't deliver enough oxygen to your heart muscle, particularly when you're exerting yourself. This can cause you to feel chest pain (angina). If a fatty plaque breaks off, it may cause a blood clot which can block blood flow to your heart (heart attack) or brain (stroke).

Types of cholesterol

Cholesterol is transported around your body attached to a protein in your blood. This combination of fat and protein is called a lipoprotein. There are different types of lipoprotein, depending on how much fat there is in relation to protein.

 HDL (high-density lipoprotein)

A small amount of cholesterol is transported as high-density lipoprotein (HDL), which is mostly protein and not much fat. HDL transports excess cholesterol from the tissues (including the walls of arteries) to your liver for disposal.

As HDL helps prevent cholesterol building up in your blood vessels, you have a decreased risk of heart disease if you have high levels of this type. HDL is often called ‘good’ cholesterol.

Women tend to have higher HDL levels than men. Physical activity can increase HDL.

LDL (low-density lipoprotein)

Most of your body's cholesterol (around 70 percent) is transported as low-density lipoprotein (LDL). It consists mainly of fat, with not much protein. LDL transports cholesterol from your liver to the cells. High levels of LDL increase your risk of CVD because LDL causes cholesterol to build up in your blood vessels. LDL is often called ‘bad’ cholesterol.

Triglycerides

Triglycerides are a different type of fat, mostly coming from fats in your food. Energy from your food that isn’t used immediately is converted into triglycerides and transported to fat cells for storage. This provides you with an important source of stored energy.

Although most triglycerides are stored as fat, low levels are also found in your blood. A raised level of blood triglycerides together with high LDL can increase your risk of heart disease, particularly if you have diabetes, smoke or have high blood pressure.

Total cholesterol (TC)

Having a high total cholesterol level is a risk factor for future health problems. However, it's important to consider the relative amounts of HDL and LDL. This is often referred to as the total to HDL cholesterol ratio (TC:HDL). You should aim for a high level of HDL and a low level of LDL (a low total to HDL ratio).

Symptoms of high cholesterol

You may only find out that you have high cholesterol if you develop symptoms of heart disease. Sometimes, yellow patches (called xanthomas) may develop around your eyes or elsewhere on your skin – these are cholesterol deposits and may show that you have high cholesterol.

Complications of high cholesterol

High cholesterol increases the risk of heart disease, arterial disease and strokes. Your GP will discuss possible complications of high cholesterol with you.

Causes of high cholesterol

There are several factors that may contribute to you having high cholesterol. These include:

  • a diet high in saturated fat
  • a lack of exercise – exercise can increase your HDL levels
  • obesity (BMI of 30 or more)
  • age and gender – your cholesterol levels generally rise with increasing age, and men younger than 55 are more likely to be affected than women, but over 55, women are more likely to be affected
  • drinking more than the recommended daily amount of alcohol
  • smoking

High cholesterol can sometimes be caused by a condition that runs in your family called 'familial hypercholesterolaemia'. About one in 500 people have this condition. It’s not caused by an unhealthy lifestyle but is passed through the family through a faulty gene.

Other conditions, such as poorly controlled diabetes, certain kidney and liver diseases, and an underactive thyroid may also cause high cholesterol. Some medicines such as beta-blockers, steroids or thiazides (a type of diuretic) may also affect blood lipid levels.

Diagnosis of high cholesterol

Your cholesterol level is measured with a blood test. Usually you will be asked not to eat for 12 hours before the test so that your food is completely digested and doesn't affect the test. Your GP or nurse may take a blood sample using either a needle and syringe, or a finger prick. You can have your cholesterol tested at your GP surgery, at hospital, or as part of a health assessment examination.

Home-testing kits for cholesterol are also available but may not be very accurate. Speak to your pharmacist about your result if you choose to use a kit.

The amount of cholesterol in your blood is measured in units called millimoles per litre of blood, usually shortened to 'mmol/litre', 'mmol/L' or 'mM'. There is no recommended level for total cholesterol or LDL cholesterol.

When looking at your cholesterol levels, your GP will consider how much HDL you have compared to LDL. This is called your total cholesterol to HDL cholesterol ratio. You can work this out by dividing your total cholesterol level by your HDL level. It’s healthiest to have high HDL, low LDL and low total cholesterol, with a total to HDL ratio of less than 4.

Who should have a cholesterol test?

Your GP should check your cholesterol levels every year if you have CVD. If you’re at high risk of CVD or you have a family history of high cholesterol, your GP should check your cholesterol. He or she will talk to you about how often it should be checked.

Treatment of high cholesterol

There are two ways to help lower high cholesterol. The first is with lifestyle changes including changing your diet, managing your weight and increasing exercise. The second is to combine lifestyle changes with cholesterol-lowering medicines.

Self-help

Healthy eating can reduce cholesterol. Your diet should be low in saturated fats in particular, and low in fat overall. Biscuits, cakes, pastries, red meat, hard cheese and butter all tend to be high in saturated fats, so cut down on these foods.

Some foods contain cholesterol. These foods include eggs, prawns and offal such as liver and kidneys. This type of cholesterol is known as dietary cholesterol and it has a much lower effect on blood cholesterol than saturated fat in your diet. You may need to cut down on these foods if your GP advises you to.

It's also important to eat plenty of fibre, especially soluble fibre, which helps to lower cholesterol. There is soluble fibre in fruits and vegetables, beans and oats. Aim to eat at least five portions of fruit and vegetables each day. Foods containing substances called plant sterols or stanols may help to lower cholesterol.

If you're overweight, losing your excess weight loss can reduce LDL levels and increase HDL levels. Increasing your physical activity may enhance the cholesterol-lowering effects of your diet.

As high cholesterol can increase your risk of heart disease, you should reduce any additional risk of developing heart disease, eg by stopping smoking.

Medicines

Your GP may prescribe cholesterol-lowering medicines if you already have heart disease, or are at high risk of getting it because you have other risk factors. The aim of treatment is to reduce your total cholesterol levels by a quarter or to less than 5mmol/L.

The main group of medicines for lowering cholesterol are the statins. Available statins include simvastatin, atorvastatin, fluvastatin, pravastatin, and rosuvastatin. They work by reducing the production of cholesterol in the liver. These medicines can have side-effects such as indigestion and muscle pains.

Other types of medicines to reduce cholesterol include fibrates, nicotinic acid and cholesterol-absorption inhibitors such as ezetimibe (Ezetrol), but these are generally less effective than statins or have more side-effects. However if you have very high cholesterol, your GP may prescribe ezetmibe with statins. Your GP can tell you more about these medicines and suggest the most suitable treatment for you.

Prevention of high cholesterol

You may be able to prevent high cholesterol by keeping to a healthy weight and eating a diet that is low in saturated fat. Try to include at least two portions of fish, of which at least one should be an oily fish such as mackerel or salmon. There is no need to take omega-3 supplements or eat spreads, yoghurts or other foods containing plant stanols or sterols. You shouldn’t smoke or drink too much alcohol, and you should take regular exercise. However, if your family has a history of high cholesterol, it may be difficult to prevent yourself from having it too.

Related topics

 

·How do the fats in my food affect my cholesterol levels?
My GP has prescribed me a statin but my partner is using a different one. Are all statins the same?
What is the normal level of cholesterol that I should have in my blood?

How do the fats in my food affect my cholesterol levels?

Fat is a good source of energy but eating too much of the wrong types of fat increases your cholesterol levels and therefore your risk of heart disease.

Explanation

Some fat is an essential part of a healthy diet, but it's important you don't eat too much of it and that you're careful about the type of fat that you eat.
Your liver turns the fat in your blood into cholesterol. Your blood then transports the cholesterol around your body. Not all cholesterol is bad for you; there is a harmful form and a protective form. The harmful form of cholesterol is called LDL or low-density lipoprotein. The protective form is called HDL or high-density lipoprotein.

Reducing the amount and type of fat that you eat helps reduce your cholesterol level. There are different types of fat in food.

  • Saturated fats – these increase cholesterol levels. Examples of foods high in saturated fat include cakes and biscuits, pastry, meat products and hard cheese.
  • Trans fats – these have a similar effect on cholesterol levels as saturated fats. Foods containing hydrogenated vegetable oil, which must be listed in the ingredients list on the label, might contain trans fats. Trans fats currently don't need to be labelled separately on food labels. They can be found in biscuits and cakes, fast food and some margarines.
  • Monounsaturated fats – these help lower harmful cholesterol levels. Examples of foods high in mono-unsaturated fats include olive oil and rapeseed oil.
  • Polyunsaturated fats – these lower both harmful and protective cholesterol levels. Examples of foods high in polyunsaturated fats include sunflower oil and soya oil.

When you're shopping for food, compare the labels so you can pick those with less total fat or less saturated fat. Buy lower fat versions of dairy foods, such as semi-skimmed or skimmed milk, and reduced-fat yoghurt, whenever you can.

Cutting down on saturated fats and replacing them with small amounts of unsaturated fats can help to reduce your cholesterol level by more than one-tenth.

There is a particular type of polyunsaturated fat called omega-3 which can help to reduce your cholesterol levels. The best source of omega-3 fats is oily fish, such as kippers, mackerel, sardines and salmon.
You should aim to eat at least one portion of oily fish per week, but not more than two portions per week if you're pregnant or breastfeeding.

If you're worried about high cholesterol, ask your GP for advice.

Further information

Sources

  • Eat well, be well. Saturated fat. Food Standards Agency. www.eatwell.gov.uk, accessed 20 September 2010
  • What is cholesterol? British Heart Foundation. www.bhf.org.uk, accessed 20 September 2010
  • Eating for your heart. British Heart Foundation. www.bhf.org.uk, accessed 21 September 2010
  • Trans fats. Eat well, be well. Food Standards Agency. www.eatwell.gov.uk, accessed 22 September 2010
  • Fat. British Nutrition Foundation. www.nutrition.org.uk, accessed 20 September 2010
  • Unsaturated fat. Eat well, be well. Food standards Agency. www.eatwell.gov.uk, accessed 22 September 2010
  • Oily fish. Eat well, be well. Food Standards Agency. www.eatwell.gov.uk, accessed 20 September 2010

 

My GP has prescribed me a statin but my partner is using a different one. Are all statins the same?

All statins available in the UK have similar cholesterol-lowering effects and a low chance of any side-effects. Your GP will prescribe you a statin at a dose that he or she thinks is suitable for reducing your cholesterol levels.

Explanation

There are five different types of statin available in the UK. Examples include simvastatin, atorvastatin, and fluvastatin. All statins work in the same way. They lower the level of cholesterol in your blood, especially low-density cholesterol (LDL) or ‘bad’ cholesterol. Statins do this by blocking a key step in the series of reactions needed to make cholesterol from simple chemicals in your liver cells. Your liver cells detect the low levels of cholesterol in the liver and suck up cholesterol from your blood, reducing the cholesterol in your blood.

Your body needs some cholesterol, so you wouldn't want a statin to remove it all, but lower cholesterol in your blood reduces your risk of heart disease, including heart attacks.

The dose you take affects how much cholesterol the statin removes from your blood. Different statins may need different doses to remove the same amount of cholesterol. These doses may also have different effects on your cholesterol levels over different periods of time. Your cholesterol levels will be regularly checked and the dose of your statin may be modified by your GP.

As with any medicine, you may have some side-effects when taking statins, but these are generally mild and similar for all types of statin. Tens of thousands of patients have used this type of medicine for periods of five years or more without any problems.

Your partner may be taking a different statin because of another health condition or because he or she is taking other medicines that might interact with a statin. Your GP will prescribe a statin that he or she thinks is suitable for you. If your GP decides to change the type or dose of statin that you're using, he or she should explain why.

Further information

Sources

  • Joint Formulary Committee, British National Formulary. 60th ed. London: British Medical Association and Royal Pharmaceutical Society of Great Britain, 2010. www.bnf.org, accessed 22 September 2010
  • Statins – All the same? Heart UK. www.heartuk.org.uk, accessed 22 September 2010
  • Lipid modification. Clinical Knowledge Summaries. www.cks.nhs.uk, accessed 22 September 2010

 

What is the normal level of cholesterol that I should have in my blood?

Too much cholesterol in your blood can increase your risk of heart problems. There is no recommended target cholesterol level unless you have cardiovascular disease (CVD) or are at high risk of CVD. For example, if you already have high cholesterol, your doctor may advise you to aim for a total cholesterol level under 5mmol/L.

Explanation

Cholesterol is a fatty substance that plays an essential role in how every cell in your body works. Your body makes most of your cholesterol and your blood transports it around the body attached to a protein. This combination of fat and protein is called a lipoprotein and there are several types of lipoprotein. Low-density lipoprotein (LDL) is called ’bad’ cholesterol because it causes cholesterol to build up in your blood vessels. High-density lipoprotein (or HDL) is often called ’good’ cholesterol because it helps prevent cholesterol building up in your blood vessels.

There is no recommendation for the ideal level of total cholesterol or LDL. Your GP considers your cholesterol levels as part of your overall cardiovascular risk, taking into account other risk factors such as your age, sex, BMI blood pressure, family history and whether you smoke, drink alcohol or have any other illness such as diabetes.

When looking at your cholesterol levels, your GP will consider how much HDL you have compared to your total cholesterol level. This is called your total cholesterol to HDL cholesterol ratio. You can work this out by dividing your total cholesterol level by your HDL level. It’s healthiest to have high HDL, low LDL and low total cholesterol, with a total to HDL ratio of less than 4.

If you have cardiovascular disease (CVD), have had a heart attack, get angina or have had an ischaemic stroke, your doctor will be aiming to help you reduce your total cholesterol level to less than 5mmol/L. He or she will offer you statins and give you advice about diet and exercise to help meet this target.

Further information

Sources

  • Simon C, Everitt H, van Dorp F. Oxford handbook of general practice. 3rd ed. Oxford: Oxford University Press, 2010: 260
  • Cholesterol and lipoproteins. Heart UK. www.heartuk.org.uk, accessed 22 September 2010
  • Lipid modification. Clinical Knowledge Summaries. www.cks.nhs.uk, accessed 22 September 2010
  • CVD Risk assessment and management. Clinical Knowledge Summaries. www.cks.nhs.uk, accessed 16 September 2010
  • Reducing your blood cholesterol. British Heart Foundation. www.bhf.org.uk, accessed 22 September 2010

Related topics

Related topics

Further information

Sources

  • Cholesterol. British Heart Foundation. www.bhf.org.uk, accessed 21 September 2010
  • Total cholesterol and low HDL cholesterol levels by sex and Government Office Region, adults aged 16 and over, 2006, England. British Heart Foundation Statistics Website. www.heartstats.org, accessed 21 September 2010
  • Cholesterol and lipoproteins. Heart UK. www.heartuk.org.uk, accessed 22 September 2010
  • Hypercholesterolemia. eMedicine. www.emedicine.medscape.com, accessed 21 September 2010
  • Reducing your blood cholesterol. British Heart Foundation. www.bhf.org.uk, accessed 22 September 2010
  • Simon C, Everitt H, van Dorp F. Oxford handbook of general practice. 3rd ed. Oxford: Oxford University Press, 2010: 260
  • Joint Formulary Committee, British National Formulary. 60th ed. London: British Medical Association and Royal Pharmaceutical Society of Great Britain, 2010. www.bnf.org, accessed 22 September 2010
  • Lipid modification. Clinical Knowledge Summaries. www.cks.nhs.uk, accessed 22 September 2010
  • Cardiovascular risk assessment and the modification of blood lipids for the primary and secondary prevention of cardiovascular disease. National Institute for Health and Clinical Excellence. www.nice.org.uk, accessed 22 September 2010

Related articles

  Published by Bupa’s Health Information Team, December 2010.   This factsheet is for people who are concerned about childhood obesity, or who would like...
Published by Bupa's Health Information Team, December 2011. This factsheet is for people who have iron deficiency anaemia, or who would like information about it. Iron deficiency...