Coronary heart disease (CHD) is when your coronary arteries (the arteries that supply your heart muscle with oxygen-rich blood) become narrowed by a gradual build-up of fatty material within their walls.
This condition is called atherosclerosis and the fatty material is called atheroma.
•In time, your arteries may become so narrow that they cannot deliver enough oxygen-rich blood to your heart. The pain and discomfort you may feel as a result is called angina.
•If a piece of atheroma breaks off it may cause a blood clot (blockage) to form.
•If it blocks your coronary artery and cuts off the supply of oxygen-rich blood to your heart muscle, your heart may become permanently damaged. This is known as a heart attack.

hat increases my risk of CHD?
A risk factor is something that that increases your likelihood of getting a disease.  There are several risk factors for CHD. The main ones are:
•Smoking
•High blood pressure
•High blood cholesterol
•Diabetes
•Being physically inactive
•Being overweight or obese
•Family history of heart disease
•Ethnic background
•Sex - men are more likely to develop CHD at an earlier age than women.
•Age - the older you are, the more likely you are to develop CHD.