stress

Meaning: Stress is a process, not just an event. A stressor is the demand or threat. In the appraisal model, primary appraisal judges whether the event is irrelevant, benign-positive, or stressful, and secondary appraisal judges whether one has the resources to cope. Stress results when perceived demands exceed perceived resources. Physiologically, the sympathetic nervous system and adrenal medulla act fast (epinephrine, fight-or-flight), while the HPA axis acts more slowly and releases cortisol. Selye's General Adaptation Syndrome describes three stages: alarm, resistance, and exhaustion. Prolonged activation of the stress response is linked to poorer health outcomes.

On the MCAT: Passages describe a study of stressors such as exams, job loss, or discrimination and ask you to predict how appraisal, coping style, or social support changes the outcome. Expect to tell eustress (positive, motivating) from distress (negative), problem-focused coping (act on the stressor) from emotion-focused coping (manage the feelings), and to name the General Adaptation Syndrome stage from a described symptom pattern. Social support and a sense of control usually buffer stress, while chronic stressors such as low socioeconomic status or discrimination wear a person down.

Common confusion: The event is the stressor; stress is the response, and it depends on appraisal. Stress is also not always harmful, since eustress can improve performance. In physics, stress means force per unit area (N/m², or Pa), which is unrelated.