Coronary heart disease, or CHD, is the term that describes what happens when your heart's blood supply is blocked or interrupted by a build up of fatty substances in the coronary arteries.
Over time, the walls of your arteries can become furred up with fatty deposits. This process is known as atherosclerosis, and the fatty deposits are called atheroma. If your coronary arteries become narrow due to a build up of atheroma, the blood supply to your heart will block your arteries.
If a coronary artery becomes partially blocked, it can cause chest pains (angina). If it becomes completely blocked, it can cause a heart attack (myocardial infarction).