The Body Under Pressure
Stress is the process by which people perceive and respond to environmental demands, or stressors, that they appraise as threatening or challenging. Physiologist Hans Selye described the body's physiological response to prolonged stress as the General Adaptation Syndrome (GAS), unfolding in three stages: Alarm (an immediate burst of arousal, mobilizing the fight-or-flight response), Resistance (continued elevated arousal as the body adapts to an ongoing demand), and Exhaustion (physiological resources become depleted if the stressor persists too long, raising vulnerability to illness). Chronic activation of the HPA axis during the resistance stage keeps cortisol elevated, which over time can suppress immune function and raise the risk of cardiovascular disease.
Whether an event counts as "stressful" at all depends heavily on interpretation. Richard Lazarus and Susan Folkman's transactional model describes two rounds of appraisal: primary appraisal asks "is this a threat, a challenge, or irrelevant?" and secondary appraisal asks "do I have the resources to cope with it?" The same event — a surprise presentation, say — can feel like a manageable challenge to one person and an overwhelming threat to another, purely based on this appraisal process.
| GAS stage | What happens |
|---|---|
| Alarm | Immediate fight-or-flight arousal |
| Resistance | Sustained arousal while adapting |
| Exhaustion | Resources depleted; illness risk rises |
Coping describes the cognitive and behavioral efforts used to manage stress once it is appraised. Problem-focused coping directly addresses the stressor to change the situation itself (e.g. making a study plan before an exam); emotion-focused coping instead manages the emotional response to a stressor that cannot easily be changed (e.g. seeking comfort, reframing, or distraction). Neither style is universally superior — problem-focused coping tends to work best for controllable stressors, and emotion-focused coping tends to work best for uncontrollable ones.
Common pitfall: assuming stress is purely a property of the event itself. In the Lazarus-Folkman model, stress is a TRANSACTION between the person and the event — the same objective event can be appraised very differently depending on the individual's resources and interpretation.
A resistance-capacity meter: a baseline needle at rest; a stressor icon appears and the needle spikes sharply (alarm), then settles onto an elevated plateau (resistance); if held too long.