What is a physical reaction to threat or perceived threat?

A physical reaction to a threat or perceived threat is primarily identified as stress. When an individual perceives a threat, whether real or imagined, the body responds with a stress reaction, commonly known as the fight-or-flight response. This physiological reaction includes increased heart rate, rapid breathing, heightened sense of awareness, and the release of stress hormones like adrenaline and cortisol. These changes prepare the body to either confront the threat or flee from it, which is a survival mechanism.

In contrast, happiness, concentration, and relaxation are emotional or mental states that do not typically arise in response to a threat. Happiness generally reflects positive feelings, concentration pertains to focusing mental energy on a task, and relaxation involves a state of calm and reduced physiological stress. These states are not characterized by the urgency and heightened arousal associated with stress reactions.