Cholesterol is a type of fat found in the blood. While it's essential for life, too much cholesterol is recognised as a risk factor for cardiovascular disease.
Although knowing your total cholesterol level is important, it's also vital to measure the levels of the different kinds of cholesterol: high-density lipoprotein (HDL), the ‘good’ cholesterol, and low-density lipoprotein (LDL), the ‘bad’ cholesterol.
High levels of HDL may help to protect your body from adverse cardiovascular events such as heart attack or stroke, while high LDL levels place you at greater risk of cardiovascular disease.
A blood test should be able to determine your total cholesterol level, including your LDL and HDL cholesterol, as well as measuring your level of triglycerides, another type of fat found in the blood. All of these measurements can help your doctor work out whether you need lifestyle changes or treatment to modify your cholesterol levels and perhaps prevent the risk of cardiovascular disease.
To get an accurate measurement of cholesterol levels, you need to fast — not consume any food or drink (other than water) — for at least 12 hours before the blood sample is collected.
Your cholesterol levels depend on a number of factors including your genetic make-up, your weight, your level of physical activity, and the types of food that you eat. If you are diagnosed as having high cholesterol (hypercholesterolaemia), you should try to reduce your cholesterol levels by eating a low-fat diet and undertaking regular exercise. Medications may also be required to reduce your cholesterol to an acceptable level.
Your cholesterol goals may vary from other people’s cholesterol goals, because they depend on your level of other risk factors for cardiovascular disease.
The 2005 Position Statement on Lipid Management released by the National Heart Foundation of Australia stressed more strongly what the 2001 Lipid Guidelines stated, which was that a person’s absolute risk of cardiovascular disease should determine what their treatment goals for cholesterol should be. That is, your doctor does not look at your cholesterol level in isolation.
For example, the target LDL-cholesterol (‘bad’ cholesterol) level to aim for in a high-risk person who already has coronary heart disease will be different to the target level in someone at low risk. Your doctor will assess all your risk factors and base their recommendations for your target cholesterol on these. That’s why you may find that your doctor has recommended that you get your cholesterol to a level that is different to what someone else is aiming for.
Those at high risk for cardiovascular disease include:
Erectile dysfunction is also increasingly being recognised as a marker for those at high cardiovascular risk.
There are other measures your doctor may use to determine your level of risk so if you are worried about your risk of heart disease, see your doctor. Of course, being in the high-risk category does not necessarily mean that you will have high cholesterol or coronary heart disease: it simply means you and your doctor should keep an eye on your cholesterol levels and other risk factors to help prevent heart disease.
The 2005 Position Statement also highlights that when treating people at highest risk of cardiovascular disease who already have coronary heart disease, doctors are finding that there are benefits in lowering LDL-cholesterol even further than 2.5 mmol/L — the evidence seems to support a target of 2.0 mmol/L in this high-risk group.
In general, your HDL-cholesterol (‘good’ cholesterol) levels should be 1.0 mmol/L or more. HDL-cholesterol is protective against cardiovascular disease, such as heart attacks, so a higher level is good. HDL-cholesterol cleans up ‘bad’ cholesterol (LDL-cholesterol) from the walls of the arteries and takes it to the liver for processing.
The level of triglycerides, another kind of fat found in the bloodstream, is recommended in the 2005 Position Statement to be less than 1.5 mmol/L — even lower than the 2.0 mmol/L recommended in the 2001 Lipid Guidelines.
The National Heart Foundation recommends that all adults aged 45 or more should be tested for high cholesterol regularly. You should discuss with your doctor your personal cholesterol goals in conjunction with the other factors that determine your risk of cardiovascular disease.
Last Reviewed: 26 October 2009