What is Adrenaline?

A hormone produced by the adrenal glands. Whenever a person faces an emergency or feels anger, shock, fear or some other strong emotion, adrenaline is passed rapidly into the bloodstream to speed up the heart rate and breathing, to make the muscles work faster and longer than usual and so to prepare the body for action. Injections of natural or synthetic adrenaline are used to treat bronchial asthma, a severe allergy, and other conditions.