Angina is a signal from your body telling you that your heart muscle is not receiving enough oxygenated blood. The heart requires an especially enriched supply of oxygen via the incoming blood flow in the coronary arteries. When the vessels that supply the heart with oxygenated blood become narrowed, the area of the heart that is not receiving the proper blood flow responds with a very painful signal called angina pectoris. Angina may feel like chest pain or pressure, shortness of breath, pain in the jaw, neck, arms, back, nausea or generalized fatigue. Each patient experiences angina differently.