What is adrenaline?

Also called epinephrine, adrenaline is released by the adrenal glands within seconds of a stressful event. It speeds up the heart, widens airways, raises blood sugar and sends blood to the muscles, while slowing digestion. Pupils dilate and senses sharpen, which is why people describe an “adrenaline rush”. It was one of the first hormones isolated, by Japanese chemist Jokichi Takamine in 1901. Adrenaline auto-injectors such as EpiPens are used to treat severe allergic reactions called anaphylaxis.