It narrows the size of the artery's opening and decreases the flow of blood and oxygen to the heart. When this happens, the muscles and nerves malfunction and pain occurs. This pain is called angina. The pain is usually located below the breastbone and often is felt in the left jaw, left shoulder and down the left arm. Although often brought on by exercise and sometimes emotional stress, it may occur at any time including during sleep.
Anginal pain is usually an ache.
Sometimes, it may feel like pressure. Angina pain is often confused with other chest pains including pain caused by heartburn, pleurisy and chest wall injuries which tend to be much sharper and often burning in nature. Angina can also occur when there is no arteriosclerosis of the coronary arteries. Although this may occur spontaneously, it is often brought on by exposure to cold, drugs such as ergotamine and cocaine, and sometimes by emotional stress. Prinzmetal's variant angina is a condition which also causes angina due to vasoconstriction.