Final answer:
Stress is an adaptive response to demands that challenge a person's psychological or physical capacity, often leading to harmful health effects when chronic.
Step-by-step explanation:
“Stress” is a person's adaptive response to a stimulus that places excessive psychological or physical demands on them. While stress responses were critical for survival against real physical threats in ancient times, modern scenarios often involve psychological stressors like public speaking or taking exams. These high-arousal situations trigger the fight or flight response, which can be less adaptive in the modern world, potentially leading to negative health outcomes including increased heart disease susceptibility and impaired immune function due to chronic stress.
The physiological basis of stress involves a three-phase process outlined by Selye's general adaptation syndrome: 'alarm reaction', 'stage of resistance', and 'stage of exhaustion'. Initially, the body's alarm reaction provides energy to manage the stressful situation. However, if the stress is prolonged, it leads to the stage of resistance, and the body remains alert to respond to stress, albeit with less intensity. If stress persists, it may result in exhaustion, where physical resources are depleted, contributing to health issues like hypertension and coronary artery disease.