What are statins?

Drugs that block the production of cholesterol and lower levels in your bloodstream. They lower the type of cholesterol that furs up your arteries by forming fatty plaques. The body needs cholesterol for tasks such as maintaining the walls of cells. But too much of the "bad" type increases the risk of heart attacks and strokes. Statins seem to not only reduce levels of cholesterol but to make fatty plaques smaller. They reduce cholesterol levels by about a third on average – but larger doses may reduce it by more.

Who needs to take them?

At first they were used only for people who had suffered a heart attack, or to prevent people who had had a stroke from having another one. Studies now suggest others might benefit – those with high cholesterol and other serious risk factors for heart disease (obesity, high blood pressure, diabetes etc). However if you have high cholesterol but no other risk factors, you may not need a statin – exercise and healthy eating might work. There are some genetic differences in how responsive people are to statins.

Do they have side effects?

They can cause muscle aches, nausea and stomach cramps. The most serious are damage to the liver, or muscle problems leading to kidney damage.

When should I see my doctor?

Talk through the risks and benefits to make sure you will benefit from them. Ask about other drugs and what you should avoid (grapefruit juice, for instance). A statin is usually for life.

(This column is for information and you should not do anything based on it except see your GP.)