On average, people in the UK have some of the highest cholesterol levels in the world. Despite that, high cholesterol doesn't usually produce any obvious symptoms so higher than ideal cholesterol levels are diagnosed with a simple blood test.
To prepare for the test, nothing should be eaten for 10-12 hours beforehand. This is called a fasting blood test and is usually done first thing in the morning between dinner the night before and a late breakfast.
The blood test may be done at a clinic by a phlebotomist or by a practice nurse or GP at your doctor's surgery. A syringe of blood may be taken or a finger prick test carried out.
Who should have a cholesterol test?
GPs will usually arrange cholesterol blood tests for people who are over 40 and those with other risk factors for high cholesterol:
- Being overweight or obese
- Having high blood pressure
- Having diabetes
- Having a family history of heart or cardiovascular problems
- Having a family history of hypercholesterolaemia or inherited high cholesterol
- Other medical conditions, age, sex and ethnic background can also make a difference
Inside your cholesterol numbers:
The blood test measures:
Total cholesterol. This is a measure of LDL cholesterol, HDL cholesterol and other lipid components.
LDL (low density lipoprotein cholesterol). LDL cholesterol can build up on the walls of your arteries and increase the chances of getting heart disease. That is why LDL cholesterol is referred to as ‘bad’ cholesterol. The lower your LDL cholesterol number, the better it is for your health.
HDL (high density lipoprotein cholesterol, also called "good" cholesterol) HDL cholesterol protects against heart disease by taking the "bad" cholesterol out of your blood and keeping it from building up in your arteries. A higher number for this cholesterol is a good sign.
Triglycerides - fats carried in the blood from the food we eat - excess calories, alcohol or sugar in the body are converted into triglycerides and stored in fat cells throughout the body.
The NHS says for healthy adults:
Total cholesterol should be 5.0 millimoles per litre (mmol/L) or lower. The average in the UK is actually around 5.5 mmol/l for men and 5.6 mmol/l for women.
LDL cholesterol should be 3mmol/L or lower
HDL level above 1 mmol/L
Triglyceride level under 1.7 mmol/L
People with higher risks, such as heart disease or high blood pressure will be set lower targets:
Total cholesterol of 4mmol/L or lower
LDL of 2mmol/L or lower
Cholesterol numbers are used to calculate the overall risk of coronary heart disease.
The ratio of total cholesterol to HDL - total cholesterol divided by HDL - should be below 4.
Doctors will set individual cholesterol targets for patients based on their overall risk factors. Treatment may involve diet changes to cut down on bad fats, increasing exercise, or taking cholesterol-lowering medication, such as statins.