Cholesterol is a fatty substance essential to normal bodily functions, but too much of it can damage your arteries.

Some foods, like eggs, offal and shellfish, make your body produce more of it. You also need to limit your consumption of saturated fat. 

There are three main types of cholesterol:

• HDL –  the so–called “good” cholesterol. It carries blood fats away from the cells to be broken down by the liver.
• LDL  –  “bad” cholesterol, which carries blood fats from the liver to the cells. If supply exceeds demand, it can cause harmful fatty build up in the arteries.
• Triglycerides – another harmful fat which contributes to thickening of the artery walls.

When someone has high levels of LDL cholesterol and triglycerides, and low levels of HDL cholesterol, it can lead to coronary heart disease and increase the risk of stroke.

You should be aiming for a cholesterol level below 5mmol/l.  You can lower your cholesterol by changing your diet and increasing activity levels as well as other healthy lifestyle changes.

If your cholesterol is high then you may be prescribed medication to lower it.  The most commonly prescribed drugs are called statins.