What is adrenaline?
Adrenaline, also called epinephrine, is a hormone released by the adrenal glands during stress or danger. It prepares the body for fight or flight by speeding up the heart and breathing.
The adrenal glands sit on top of the kidneys. When the brain senses a threat, it signals them to release adrenaline into the blood within seconds. Adrenaline raises the heart rate and blood pressure, opens the airways, sends more blood to the muscles and releases sugar for quick energy. The pupils widen, and senses sharpen.
This response helped our ancestors escape predators or fight. Today, it can be triggered by exciting or stressful situations, like a roller coaster ride, public speaking or an exam. The feeling of an adrenaline rush includes a pounding heart, shaky hands and sweating.
A life-saving medicine
Epinephrine is also an important medicine. Auto-injector pens deliver it to treat severe allergic reactions, called anaphylaxis, which can block airways. Doctors also use it in cardiac arrest to help restart the heart.
Did You Know?
Adrenaline was one of the first hormones to be isolated. Japanese chemist Jōkichi Takamine purified it in 1901.
This answer is general information, not medical advice. For a personal health question, talk to a doctor.