The fight-or-flight response is a natural reaction that occurs when we face danger or stress. It prepares our body to either confront the threat (fight) or escape from it (flight). When we sense danger, our brain sends signals that trigger the release of hormones like adrenaline, increasing our heart rate and energy levels. This helps us react quickly to the situation. This response is essential for survival and has been crucial throughout human evolution. For example, when early humans encountered predators, the fight-or-flight response allowed them to either defend themselves or flee to safety. Today, we still experience this response in stressful situations, like public speaking or taking an exam.