0800 022 4524

What is Cholesterol?


Cholesterol is a fatty substance carried around the body by proteins. When cholesterol and proteins are combined, they are called lipoproteins. There are two main types of lipoproteins:

  • Low-density lipoproteins (LDL) is known as the bad type of cholesterol. LDL carry cholesterol from your liver to the cells that need it. 
  • High-density lipoprotein (HDL) is known as the good type of cholesterol. HDL carry cholesterol away from the cells and back to the liver to be broken down.


Too much bad cholesterol (LDL) in your blood can cause fatty material to build up in your artery walls. The risk is particularly high if you have a high level of bad cholesterol and a low level of good cholesterol.

If you need to have your cholesterol measured, it will be in units called millimols per litre of blood(mmol/l). You should aim to have a total cholesterol level under 4mmol/l especially if you are at risk of, or already have, heart and circulatory disease. You should also aim to have your LDL under 2 mmol/l and your HDL above 1 mmol/l.