The term angina describes chest pain caused by too little oxygen to the heart muscle. An angina episode is not the same as a heart attack, because the pain is temporary and it seldom causes permanent damage to heart muscle.

Angina is divided into two categories: angina of effort and variant angina. Angina of effort is caused by the narrowing of the arteries (atherosclerosis). The narrowed arteries don't allow enough blood through to the heart muscle during periods of exercise, stress, or excitement. Due to atherosclerosis, people with angina of effort have an increased risk of heart attack.

Variant angina is uncommon and occurs independently of atherosclerosis. Variant angina is not related to excessive work by the heart muscle. Research indicates that it is caused by heart artery muscle spasm that is too brief or too weak to cause an actual heart attack.

Angina causes a pressing pain...