What is meant by the "fight or flight" response?

The "fight or flight" response refers to a physiological reaction that occurs in response to perceived threats or danger. This biological mechanism is a fundamental part of the body's autonomic nervous system, specifically engaging the sympathetic nervous system. When faced with a stressful situation, the body prepares to either confront the threat (fight) or escape from it (flight).

During this response, several physiological changes take place, including increased heart rate, heightened blood pressure, rapid breathing, and the release of stress hormones like adrenaline and cortisol. These changes equip the individual with the necessary tools to either face the danger or flee from it, thereby enhancing survival in potentially harmful situations. This response is not about emotional regulation or social interaction, but rather a primal reaction to threats that has evolved for protection.