30. Stress and distress - etiology, pathogenesis, clinical manifestations.

Stress and distress – etiology, pathogenesis, and clinical manifestations

Stress

• A state of threatened homeostasis, in which the body responds to internal or external challenges ("stressors") via adaptive physiological and behavioral mechanisms.

Distress

• Pathological, harmful form of stress, when adaptive responses are inadequate or become maladaptive, leading to dysfunction or disease.

Etiology (Causes)

1. 1 Physical stressors

• Trauma, burns, surgery.
• Extreme temperatures.
• Intense exercise.

1. 2 Psychological stressors

• Emotional conflicts, anxiety, depression.
• Social isolation.
• Work or academic pressure.

1. 3 Biological stressors

• Infections.
• Chronic diseases (e.g., cancer, diabetes).

Pathogenesis

General Adaptation Syndrome (Hans Selye model)

Stage 1: Alarm reaction

• Immediate response to stressor ("fight or flight").
• Activation of hypothalamic-pituitary-adrenal (HPA) axis:
• Hypothalamus → corticotropin-releasing hormone (CRH).
• Pituitary → adrenocorticotropic hormone (ACTH).
• Adrenal cortex → cortisol release.
• Activation of sympathetic-adrenal-medullary system:
• Release of catecholamines (epinephrine, norepinephrine).

Stage 2: Resistance (adaptation)

• Continued secretion of cortisol and catecholamines maintains alertness and energy supply.
• Physiological parameters stabilize at new set points.

Stage 3: Exhaustion

• Prolonged stress depletes adaptive resources.
• Leads to organ dysfunction and disease (distress phase).

Molecular and cellular mechanisms

• Increased glucocorticoids → protein catabolism, gluconeogenesis, immunosuppression.
• Catecholamines → increased heart rate, blood pressure, metabolic rate.
• Prolonged high cortisol → insulin resistance, central obesity, osteoporosis.

Clinical Manifestations

Short-term (acute stress)

• Tachycardia, hypertension.
• Increased respiratory rate.
• Sweating, tremors.
• Heightened alertness and anxiety.
• Hyperglycemia (mobilized energy substrates).

Long-term (chronic stress / distress)

• Cardiovascular: hypertension, atherosclerosis, arrhythmias.
• Metabolic: hyperglycemia, diabetes mellitus, dyslipidemia.
• Immune: increased infections, slower wound healing, autoimmunity.
• Neuropsychiatric: anxiety, depression, sleep disturbances, memory problems.
• Gastrointestinal: peptic ulcers, irritable bowel syndrome.
• Musculoskeletal: muscle tension, headaches.

Distress-specific manifestations

• Symptoms exceed coping capacity → maladaptive.
• Contributes to psychosomatic diseases (e.g., tension headache, ulcerative colitis flare).
• Emotional exhaustion, reduced motivation, social withdrawal.