What hormone triggers the fight or flight response?

The hormone that triggers the fight or flight response is epinephrine. This hormone, also known as adrenaline, is released by the adrenal glands in response to stress or perceived danger. When faced with a threatening situation, the body experiences a surge of epinephrine, which prepares it to either confront the threat or escape from it. This response is characterized by increased heart rate, heightened blood pressure, dilated airways, and increased blood flow to the muscles, all of which are essential for rapid physical reactions.

In contrast, cortisol, another hormone released during stress, does play a role in the body’s long-term stress response but is not the primary trigger for the immediate fight or flight reaction. Norepinephrine is involved in the fight or flight response as well, but it mainly helps to maintain arousal and alertness rather than being the primary hormone responsible for triggering the response. Insulin is related to glucose metabolism and is not involved in the response to stress or danger.