Angina is a type of temporary chest pain, pressure or discomfort that occurs when the heart is not getting enough oxygen. The most common cause of angina is coronary artery disease, which occurs when the coronary arteries that supply the heart with oxygen-rich blood become blocked with deposits of fatty plaque.

More than 9 million Americans suffer from angina, according to the American Heart Association.

If the angina occurs in predictable situations, such as during exertion or exercise, it is known as stable angina. However, if the painful episodes occur without warning, last longer than normal angina episodes and occur more frequently, it is known as unstable angina. This is a dangerous medical situation that requires prompt medical attention. Unstable angina may signal an impending heart attack.

Treatment for angina usually includes a combination of lifestyle changes (e.g., quitting smoking) and medication (e.g., nitrates). If coronary artery disease is present, treatment options may also include medication, balloon angioplasty (with or without stenting) and bypass surgery.