The Nature of Stress

2.1 Defining Stress

Stress can be understood from three perspectives:

Perspective	Definition	Example
Stimulus-based	Stress as an external event or condition	A tight deadline, a public speech
Response-based	Stress as the body's reaction (Selye's view)	Raised heart rate, cortisol release
Transactional	Stress as mismatch between demand and perceived coping capacity (Lazarus & Folkman)	"This exam is too hard for me"

The transactional model is the most widely accepted today because it explains why the same event causes stress in one person but not another.

Stressors are stimuli that cause stress. They can be:

• Physical: Extreme temperature, noise, injury, illness
• Psychological: Fear, anxiety, conflict, uncertainty
• Social: Interpersonal conflict, social isolation, discrimination
• Occupational: Role conflict, work overload, job insecurity

Eustress vs. Distress:

• Eustress (from Greek "eu" = good): Moderate stress that motivates, focuses attention, and improves performance. Example: excitement before a presentation.
• Distress: Excessive or chronic stress that overwhelms coping capacity, impairing health and performance.

The Yerkes-Dodson Law (inverted U-curve) shows that performance improves with increasing arousal/stress up to an optimal point, after which it declines. Very low stress = boredom; very high stress = anxiety and breakdown.

2.2 Hans Selye's General Adaptation Syndrome (GAS)

Hans Selye (1936) described the body's universal response to stress in three stages:

• Stage 1: Alarm Reaction: Sympathetic nervous system activated; adrenaline/cortisol released; fight-or-flight response. Temporary drop in resistance.
• Stage 2: Resistance: Body adapts to the stressor; physiological arousal remains elevated; coping mechanisms activated. Resources begin to deplete.
• Stage 3: Exhaustion: Adaptive reserves depleted; immune suppression; psychosomatic illnesses, breakdown, or even death if stress continues.

Physiological correlates: During the alarm stage, the hypothalamic-pituitary-adrenal (HPA) axis is activated, releasing cortisol (the "stress hormone") from the adrenal cortex. Cortisol increases blood sugar, suppresses digestion and immune function, and mobilises energy for immediate survival. Chronic cortisol elevation is linked to hypertension, diabetes, and depression.

2.3 Sources of Stress (Stressors in Detail)

Category	Specific Stressors	Impact
Life Events	Marriage, divorce, bereavement, relocation	Holmes-Rahe scale: death of spouse = 100 life change units
Daily Hassles	Traffic, bills, minor conflicts	Accumulated hassles predict health better than major events (Kanner et al.)
Catastrophes	Natural disasters, war, pandemic	PTSD, collective trauma
Occupational	Role overload, conflict, ambiguity	Burnout, absenteeism
Environmental	Noise, crowding, pollution	Chronic physiological arousal