What is cholesterol


Cholesterol is a fatty, waxy substance that comes from two sources: your body and your diet.1
Your body uses some of that cholesterol to build healthy cells and tissues. You take in some cholesterol in your diet; however, your body is also naturally able to make the cholesterol it needs.
body diet

Familial Hypercholesterolaemia

Some people get high levels of cholesterol from lifestyle choices like diet or smoking. Other people have high cholesterol that starts from childhood, because of a genetic (inherited) condition called familial hypercholesterolaemia. Click on the Play video button to learn more about familial hypercholesterolaemia.

Types of cholesterol

There are two kinds of cholesterol: HDL (also called ‘good’) cholesterol helps protect you against heart disease. LDL (also called ‘bad’) cholesterol, along with other substances, can build up in your arteries as fatty deposits known as plaque.1,2
High cholesterol typically doesn't cause any signs or symptoms. So, the only way to know if you have it is to get a blood test that measures the fats in your blood. Your healthcare team can do a simple blood test to measure your cholesterol levels.3
The blood test will show your levels of:

LDL-C (Low Density Lipoprotein Cholesterol)

LDL-C (also called ‘bad’ cholesterol), along with other substances, can build up in your arteries as fatty deposits known as plaque.1,2
Over time, plaque build-up can clog your arteries, which can slow down or even block blood flow. If a plaque bursts it can block a blood vessel causing a heart attack or stroke.

Normal Artery

Clear Blood Flow

Cholesterol Building in Artery

Plaque blocks blood flow

Cholesterol Building in Artery

Plaque blocks blood flow

High cholesterol, whether it’s caused by a genetic health condition or by lifestyle factors, can be dangerous for your health. The trouble is, people often don’t have any symptoms of high cholesterol until something serious happens like a stroke or heart attack.2,4

Eat more colours1

Eat a colourful, varied, fresh diet full of wholegrains, unprocessed foods, fruit and vegetables. Healthy doesn’t have to be boring – there’s a world of ingredients and flavours out there to discover.

Move more1

Do some exercise – It doesn’t matter what it is, as long as you enjoy it, you stick at it and you go regularly. It could be walking the dog, dancing, golf – whatever gets your moving, it will all help!

Stop smoking

12 months after giving up smoking, your risk of developing heart disease could fall by up to a staggering 50%.5 It’s never too late to kick the habit.

Diet and lifestyle changes are a good start to lowering bad cholesterol (LDL-C), but for some people, medication may also be needed.6

Statins are the most common type of medication used to lower LDL-C and have been shown to reduce the risk of heart attack and stroke. They include atorvastatin, fluvastatin, pravastatin, rosuvastatin and simvastatin. Statins work by blocking a substance in the body that is needed for making cholesterol.7 Depending on your risk level, you may need additional medication to reduce your level of bad cholesterol (LDL-C) even further, such as a medication called ezetimibe. You may also find you cannot take statins or high doses of statins due to uncomfortable side effects. In these cases, your doctor will consider LDL-C lowering medications including Repatha®, either alone or, where possible, in combination with a statin.


  1. Heart UK. What is cholesterol? Available at: www.heartuk.org.uk/cholesterol/what-is-cholesterol [Last accessed: May 2021]
  2. Heart UK. What is high cholesterol? Available at: www.heartuk.org.uk/cholesterol/what-is-high-cholesterol [Last accessed: May 2021]
  3. Centers for Disease Control and Prevention. About cholesterol. Available at: www.cdc.gov/cholesterol/cholesterol_screening.htm [Last accessed: May 2021]
  4. NHS. What is high cholesterol? Available at: www.nhs.uk/conditions/high-cholesterol/ [Last accessed: May 2021]
  5. Heart UK. Quit smoking. Available at: www.heartuk.org.uk/healthy-living/quit-smoking [Last accessed: May 2021]
  6. HSE. Cholesterol, high. Available at: www.hse.ie/eng/health/az/c/cholesterol,-high/ [Last accessed: May 2021]
  7. NHS. Statins. Available at: www.nhs.uk/conditions/statins/ [Last accessed: May 2021]