What Happens in the Body When We Feel Fear or Anxiety?

Above: Incoming sensory information is processed in many brain regions. This information is sent to the amygdala, the sympathetic nervous system, and the hypothalamus. The central and basolateral amygdala processes fear, anxiety, and emotional experiences and sends information to the sympathetic nervous system to prepare the body for an emergency situation - fight or flight.

The hypothalamic-pituitary-adrenal axis is alsoactivated. This system is slower than the fight or flight response, and it releases cortisol into the blood stream.