Medicine & Health
What is Adrenaline?
Adrenaline (also called epinephrine) is a hormone released by the adrenal glands that powers your 'fight or flight' response. In moments of stress or danger it floods the body, sharpening focus and preparing you for fast action.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains adrenaline.
Key things to understand
- 1It is released by the adrenal glands when the brain senses stress or danger.
- 2It speeds the heart, widens the airways, and pushes blood and energy to the muscles.
- 3It sharpens alertness and dulls pain for a short burst — the 'adrenaline rush'.
- 4It works fast and fades fast, unlike the slower-acting stress hormone cortisol.
- 5Injected adrenaline (an EpiPen) can reverse a severe allergic reaction.
Frequently asked questions
- What does an adrenaline rush feel like?
- A racing heart, heightened alertness, rapid breathing, and a burst of energy — your body priming itself to act fast.
- What is the difference between adrenaline and cortisol?
- Adrenaline acts within seconds for an immediate burst; cortisol acts more slowly to sustain the body's response to longer stress.
- How does an EpiPen use adrenaline?
- It injects a dose of adrenaline that quickly opens the airways and tightens blood vessels, counteracting a life-threatening allergic reaction.