Having 'high cholesterol' is a medical condition which does not have any symptoms but which puts you at higher risk of other conditions such as heart attacks and strokes. Cholesterol is produced by the liver and is found in the blood. High cholesterol can be caused by genetic factors but also lifestyle factors. The risk of having high cholesterol can therefore be decreased by having a healthy lifestyle.
What is High Cholesterol?
Cholesterol is a fatty substance (lipid) found in the blood and produced by the liver. It is also found in some foods.
Cholesterol is carried in the blood by proteins called lipoproteins. There are good and bad lipoproteins:
Low-Density Lipoproteins (LDL): These carry cholesterol from the liver to the cells where it is needed. If the cells already have enough then the cholesterol can build up in the arteries. LDL's are the bad lipoproteins.
High-Density Lipoproteins (HDL): These carry cholesterol from the cells back to the liver where it can be broken down. The HDL's are good lipoproteins.
Having high cholesterol increases the risk or other conditions such as coronary heart disease and strokes. This is because cholesterol can build up in the walls of the arteries (blood vessels pumping blood from the heart). This causes an increase in blood pressure, a restricted flow of blood to the heart, the brain and the rest of the body.
What is a High Cholesterol Level?
Cholesterol is measured using a blood test which shows the levels of LDL's, HDL's and triglycerides in the blood. The units used to measure are called millimoles per litre of blood (mmol/L).
Current UK Government recommendations for a healthy adult are that the total cholesterol reading is under 5 mmol/L, with the level of LDL's (bad cholesterol) being under 3 mmol/L.
For those who are at higher risk (such as those with a family history of heart problems, existing heart disease, diabetes or high blood pressure) should aim to keep their total cholesterol level under 4 mmol/L, with LDL's under 2 mmol/L.
What Causes High Cholesterol?
Lots of factors can contribute to someone developing high cholesterol. These include:
- An unhealthy diet including lots of saturated fat
- A lack of exercise
- Carrying excess weight
- Drinking excess alcohol
- High blood pressure
- Kidney disease
- Liver disease
- A family history of heart conditions, stroke or high cholesterol
- Ethnicity - People of Indian, Bangladeshi, Sri Lankan or Pakistani descent have an increased risk of high cholesterol.
Initial treatment of high cholesterol involves making lifestyle changes to improve diet, increase exercise levels, reduce alcohol intake and stop smoking. If all of these factors are addressed but the cholesterol level does not improve within a few months, then cholesterol-lowering medication will be prescribed.
Dietary changes should mostly involve a decrease in saturated fat intake. Saturated fat is fat which is solid at room temperature, for example, butter (and other spreads), meat fat and cheese as well as sweet products such as cream, chocolate, cakes, and biscuits.
There are several different medications which may be prescribed to help to lower cholesterol. These include:
Statins - This helps to block the enzyme in the liver which produces cholesterol. Statins are usually taken for life in those who are at a high risk of heart disease.
Aspirin - This may be prescribed in a low daily dose to reduce blood clots forming.
Niacin - This is a B vitamin. In high doses, it can reduce LDL's and increase HDL's. However, it does have side effects and can cause liver problems in the long-term so is not commonly prescribed.
Ezetimibe - This blocks the absorption of cholesterol into the bloodstream. It is less effective than statins but has fewer side effects.