The Stress Cascade

Here is what fires inside you the moment anxiety hits.

Your amygdala spots a possible threat and pings the hypothalamus, which floors the sympathetic nervous system — your body's gas pedal.

Adrenaline hits the bloodstream. Heart rate jumps, blood pulls away from your gut toward big muscles, pupils widen, and breathing goes fast and shallow. If the threat sticks around, cortisol follows to keep you wired and to put digestion, repair, and reproduction on hold.

The first alarm fires in a fraction of a second. The full flood builds over the next several seconds — so your body is braced for combat before your thinking mind has finished sizing up the situation.