Coronary heart disease (CHD) is usually caused by a build-up of fatty deposits on the walls of the coronary arteries. The fatty deposits, called 'atheroma', are made up of cholesterol and other waste substances.

The build-up of atheroma on the walls of the coronary arteries makes the arteries narrower and restricts the flow of blood to the heart. This process is called 'atherosclerosis'.

Atherosclerosis can be caused by lifestyle habits and other conditions such as:

• smoking
• high cholesterol
• high blood pressure (hypertension)
• diabetes.

If your doctor thinks you are at risk of CHD, they may carry out a risk assessment. This involves asking about your medical and family history, asking about your lifestyle and requesting a blood test.

Sources: NHS Choices, UK (Causes of heart disease)