An angina is chest pain caused by reduced flow of blood to the heart muscle. It is not a heart attack, but may be a warning of an impending heart attack.

Angina specifically occurs when the heart muscle is not receiving enough oxygen, and coronary artery disease causes chest pain. With angina, however, no permanent damage is done to the heart muscle. Approximately 6.2 million people in the U.S. have been diagnosed with angina. The symptoms of angina are similar to those of a heart attack. They are most commonly described as a squeezing, burning, tightness, fullness, or pressure across the chest.

This discomfort may radiate to the shoulder, arms (especially the left), neck, jaw, teeth, earlobes, as well as the upper back between the shoulder blades. Numbness or tingling in the arms or hands may occur. Angina can be mistaken for indigestion. It occurs with exertion and resolves with rest. Usually it lasts only a few minutes. Sometimes an onset can occur during a heavy meal, cold weather or increased emotional stress. This is called stable angina. Unstable angina exists when the angina worsens. Unstable angina is defined as more frequent episodes of anginal chest pain with less exertion, anginal chest pain at rest, or new onset of severe angina. This condition can quickly lead to a heart attack. Nitrates (such as nitroglycerin) are used to relieve chest pain. This can be given sublingually or intravenously.