Why cholesterol matters

What is coronary heart disease?
The single biggest killer in the UK is coronary heart disease. Like any muscle, the heart needs a constant supply of oxygen and nutrients, which are carried to it by blood in the coronary arteries. When these arteries become narrowed or clogged and cannot supply enough blood to the heart, the result is CHD.

Measuring cholesterol
Blood cholesterol levels are measured by means of a small blood sample with a syringe and needle, or from a finger prick. The initial test measures the total amount of cholesterol, good and bad. This level can vary from day to day, or even during the day, so a series of tests may be needed if your doctor has any worries that your results may be high. Further testing may be done to measure the exact amounts of the various different types of lipoprotein. The units used to measure blood levels of cholesterol are mmol/l - or millimoles per litre.

What's a safe level?
Not all doctors agree on exactly what the normal or 'safe' level of cholesterol in the blood should be but most authorities agree that, in adults aged under 60, total cholesterol should be less than 5 mmol/l; LDL should be less than 3.0 mmol/l; and HDL should be more than 1 mmol/l for men, or 1.2 mmol/l for women.

If you are at high risk of developing CHD within the next 10 years, total cholesterol should be even lower ? below 4mmol/l, with LDL-cholesterol below 2 mmol/l. This usually means having to take a cholesterol-lowering drug called a statin.

An estimated 72% of men and 69% of women aged 35 to 64 years have raised total cholesterol levels above 5mmol/l in the UK, with an average of 5.8mmol/l. This means that many people in this country have a cholesterol level that carries health risks. The higher the level of cholesterol, the higher the risk of heart disease.

Those at risk
If you have heart disease or risk factors for heart disease, such as diabetes, a family history of the disease, or if you smoke, you should pay even more attention to cholesterol level. Your doctor may suggest treatment to lower your cholesterol to keep it within a healthy range.

Treatment
If your cholesterol was found to be high on routine testing, or you have already had problems related to arterial disease, your doctor will probably advise medication and lifestyle changes.