The hardening of the arteries is normally called atherosclerosis. It occurs when the normal lining of the arteries are damaged. This makes the artery walls thick. The deposits of fat and plaque can build up there and this cause narrowing and in extreme cases blockage of the arteries.

In coronary artery disease which is a form of atherosclerosis, the arteries that supply blood to the heart is narrowed. This decreases the supply of oxygen-rich blood to the heart. Extra strain on the heart may result in chest pain and other symptoms like short breathing.

It it is not treated the result is heart attack. If the symptoms are there you must go to your doctor immediately. If it is severe go to the hospital directly or call for an ambulance immediately.