A fear of heights, also known as acrophobia, manifests itself physically by activating the fight or flight response. When you are exposed to a tall building or are on top of a tall bridge, you start to have panic symptoms as you go to the top of the skyscaper or go on the bridge. The exposure to heights triggers the amygdala, a part of the brain that plays a central part of the fear response. When the amygdala is activated, then it triggers both the sympathetic nervous system and the HPA axis (hypothalamic-pituitary-adrenal axis), which then releases adrenaline and other stress hormones. These stress hormones are responsible for the physical symptoms of your fear of heights, which includes muscle tension, shortness of breath, racing heartbeat, sweating, lump in the throat, and butterflies in the stomach.
