What is the body's reaction to changes in the environment known as?

The body's reaction to changes in the environment is known as stress. Stress is a physiological and psychological response to perceived challenges or threats, which can include various environmental changes. When faced with stressors, the body activates its fight-or-flight response, leading to a release of stress hormones like adrenaline and cortisol. This reaction prepares the body to manage or escape the situation, which can be beneficial in short-term scenarios where quick responses are needed.

In this context, anxiety refers to a feeling of worry or fear often experienced in response to stress, but it is not synonymous with the physiological reaction itself. Resilience is the ability to bounce back from stress or adversity, which pertains more to how individuals cope with stress rather than the stress response itself. Fatigue is a state of physical or mental weariness, often resulting from prolonged stress but not directly the body's reaction to changes in the environment. Thus, stress is the term that accurately describes the immediate and multifaceted response to environmental changes.