The fight-or-flight response is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival. It is also known as the acute stress response and is a survival mechanism that enables people and other mammals to react quickly to life-threatening situations. The response begins in the brain, where the amygdala interprets images and sounds and sends a distress signal to the hypothalamus, which activates the sympathetic nervous system. The sympathetic nervous system triggers the fight-or-flight response, providing the body with a burst of energy so that it can respond to perceived dangers. The physiological changes that occur during the fight-or-flight response are activated to give the body increased strength and speed in anticipation of fighting or running. Some of the specific physiological changes and their functions include increased blood flow to the muscles, increased blood pressure, heart rate, blood sugars, and fats in order to supply the body with extra energy.

In addition to physiological reactions, there is also a psychological component to the fight-or-flight response. Automatic reactions include a quickening of thought and an attentional focus on salient targets such as the source of the threat and potential avenues for escape. Secondary psychological responses can include appraisals about the meaning of the body reactions. For example, patients with panic disorder often misinterpret fight-or-flight responses as signs of impending catastrophe.

The fight-or-flight response is an important reaction that we all have and need, but it’s meant for authentic stress and danger. Everyone is going to have it in varying degrees for different reasons, but learning to slow down, be aware, and conceptualize what’s actually happening can help control the response. Relaxation techniques such as deep abdominal breathing and focus on a soothing word can help counter the stress response by eliciting the relaxation response.