INDERAL works by affecting the body's response to some nerve impulses, especially in the heart. As a result, it decreases the heart's need for blood and oxygen and therefore reduces the amount of work the heart has to do. It also widens the blood vessels in the body, as well as helping the heart to beat more regularly. INDERAL belongs to a group of medicines called beta-blockers. INDERAL tablets are used to treat or prevent a number of conditions, most of which are related to the heart. to lower high blood pressure, also called hypertension to prevent angina to treat or prevent heart attacks, or reduce your risk of heart problems following a heart attack to treat irregularities in heart beat, including those caused by anxiety essential tremor (shaking of head, chin, hands) phaeochromocytoma Fallot's Tetralogy to prevent migraine headaches