Chapter 7: Physical Disorders and Health Psychology

The transition in modern medicine from primarily infectious disease management to addressing chronic lifestyle-related conditions underscores the necessity of understanding psychological and behavioral contributions to illness. Health psychology as a discipline investigates how psychological interventions and lifestyle modifications can prevent disease, enhance medical treatment effectiveness, and promote overall wellness. The chapter introduces foundational stress physiology through Hans Selye's model of the stress response, which describes three sequential phases: an initial alarm reaction, a sustained resistance phase, and eventual exhaustion when coping resources become depleted. The hypothalamic-pituitary-adrenal axis and cortisol regulation represent the biological mechanisms through which chronic stress impairs immune function, amplifies inflammatory responses, and damages neural structures critical for memory and emotion regulation. Self-efficacy, the perception of personal capability to manage stressors effectively, emerges as a protective factor in stress resilience and health outcomes. Psychoneuroimmunology establishes the bidirectional relationship between psychological state and immune system competence, demonstrating that chronic stress compromises resistance to infections, autoimmune conditions, and malignant disease progression. The chapter applies these principles to specific medical conditions including acquired immunodeficiency syndrome, where psychological support accelerates disease management; oncology, where coping mechanisms and social networks influence survival; and cardiovascular disease, where personality patterns such as time urgency and hostility increase pathological risk. Pain perception is reconceptualized through gate control theory as an experience modulated by psychological, social, and biological variables rather than a direct sensory transmission, with endogenous opioid systems providing natural pain regulation. Evidence-based psychosocial treatments including biofeedback for physiological self-regulation, relaxation techniques and mindfulness meditation for stress reduction, and cognitive-behavioral therapy for maladaptive health-related thoughts and behaviors provide practical clinical applications of these principles.