The Science Behind the “Fight or Flight” Response

The adrenal glands flood the body with adrenaline in seconds.
Heart rate, blood pressure, and breathing speed up instantly.
Blood moves from digestion to muscles for action.
Pupils widen for sharper focus.
Glucose is released to fuel quick movement.
Once danger passes, cortisol helps you recover.
This ancient response still activates in modern stress.
Chronic activation wears down the body’s defenses.
Deep breathing signals the body to end the alert.
“Fight or flight” keeps you alive—but rest keeps you healthy.