Beta blocker is a drug that relieves stress on the heart by blocking the effects of adrenalin in the heart cells and blood vessels.
Beta blockers have been shown to be particularly successful in reducing heart attacks among those who have already suffered them.
Physicians often use beta blockers in treating heart patients, people who have hypertension, and persons suffering from angina and irregular heart beat.
Beta blockers are also used to treat migraine headaches, hyperthyroidism, and glaucoma.
Beta blockers are not prescribed for persons suffering from asthma or lung disorders, as they tend to constrict breathing passages.

Beta blockers should be used with caution in patients with diabetes mellitus.