Coronary heart disease (CHD), previously called ischemic heart disease, is when your coronary arteries become narrowed by a gradual build-up of fatty material within their walls. These arteries supply your heart muscle with oxygen-rich blood.
This condition, known as atherosclerosis, is caused by the build-up of fatty material called atheroma inside the artery walls.
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 are 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 heart attack.