Adrenaline is a hormone released from the adrenal glands that prepares your nervous system to fight or flee, and your body makes it in response to a stressor or threat. It’s an amazing thing to have coursing through your system when facing danger—people have been known to lift cars off children and run faster than they ever had due to adrenaline. It increases the flow of blood to muscles, releasing sugar into your bloodstream, along with a cascade of other effects that make your body alert and more able to fight off an attacker or outrun a flood.
Source: https://www.endocrineweb.com/adrenaline