"Stress": Definitions Across Physics, Medicine, Psychology & More

The term stress has distinct technical meanings across disciplines:

Physics & Engineering

• Physics: Internal force per unit area within a material resisting deformation (σ = F/A). Units: Pascals (Pa).
• Engineering: Same concept—applied load intensity; analyzed as normal, shear, tensile, compressive stress.

Medicine & Physiology

• Physiologic stress: The body's nonspecific response to any demand (Selye's General Adaptation Syndrome: alarm, resistance, exhaustion). Involves HPA axis, cortisol, catecholamines.
• Psychological stress: Perceived threat exceeding coping resources; cognitive-emotional appraisal (Lazarus).

Psychology

• Emotional/physical tension from adverse or demanding circumstances. Acute vs. chronic; eustress (beneficial) vs. distress (harmful).

Finance

• Financial stress: Pressure on liquidity, solvency, or cash flow; risk of default/bankruptcy. Stress testing models adverse scenarios.

Linguistics

• Prosodic emphasis on a syllable (word stress) or word (sentence stress), realized via pitch, duration, intensity.

Context determines meaning—always clarify the domain.