Why Your Body Freezes, Flees, or Fights Under Stress
Psychology Today | 01.07.2026 20:50
Similar to stress, when we feel fearful, the amygdala activates the HPA axis, releasing cortisol, epinephrine (adrenaline), norepinephrine, and acetylcholine. These hormones stimulate our nervous systems immediately, but their effects can be felt for up to an hour once they’re released. Depending on the extent of the fear, the release of these hormones can activate one of several fear responses: fight, flight, or freeze. A flight response activates under greater levels of fear than the fight response, and the freeze response activates under even greater levels as a last resort against danger.
