Angina pectoris, commonly referred to as angina, is a temporary pain or tightness that starts in the chest and sometimes radiates to other parts of the body, particularly the arms, neck, jaw or back. It comes on suddenly–often in response to exertion, emotional stress or exposure to cold–and is usually of short duration. It is caused by a reduction in blood flow through the coronary arteries, the blood vessels that nourish the heart muscle. This reduced blood flow results in a reduction in oxygen reaching a portion of heart muscle, …