What is cholesterol?
Cholesterol is a fat substance that is present in the blood. Most cholesterol is in fact produced inside the body by the liver, and cholesterol we ingest from food is called 'dietary cholesterol' - interestingly this dietary cholesterol only has a small influence on your blood cholesterol level.
What are the different types of cholesterol?
There are two different types of blood cholesterol, based on the proteins that carry the cholesterol in the bloodstream - these are called lipoproteins...
High Density Lipoproteins (HDL or HDL-C)
These are regarded as the 'good' type of cholesterol as they help to stop the buildup of hard plaque in the arteries. They carry a smaller quantity of cholesterol than the Low Density Lipoproteins.
Low Density Lipoproteins (LDL or LDL-C)
These are regarded as the 'bad' type of cholesterol and are understood to be the source of plaque buildup in the arteries.
What are triglycerides?
As well as cholesterol, blood also contains another fat type which also raises cardiac risk, called triglycerides. These are stored in the body's fat deposits as an energy source for the body in between meals. Any excess calories in the bloodstream are converted into triglycerides. Low levels of HDL are associated with high triglyceride levels and some evidence that high triglyceride levels are associated with cardiac risk.
How are cholesterol levels measured?
Your doctor can measure your blood cholesterol levels with a simply blood test. They will make a decision as to whether you need a lipid altering medication based on your cardiovascular risk and medical history.
Remember that blood cholesterol level is only one indicator of cardiac risk and on its own may not be significant - some people with high cholesterol levels still only have a low cardiac risk.
What treatments are available for high cholesterol?
High cholesterol can be reduced either with medication or by making lifestyle changes. If you doctor recommends medication you may need to take a type of drug called a statin, which reduces cholesterol levels.
Read our section on Nutrition and Exercise to see how you can reduce your cholesterol level by making lifestyle changes.