Health, Illness, and Disease Class Notes

Health, Illness, and Disease Class Notes

Course Information

• Direct Entry Medicine Course

• Foundations for Practice 1

• Lecturer: Dr. Lisa Mellon

• Date: 2025-26

• Institution: RCSI (Royal College of Surgeons in Ireland)

Learning Outcomes

1. Define health and illness

2. Distinguish health, illness, and disease

3. Explain the biopsychosocial model of health

4. Outline the perception of symptoms and illness

5. Describe the common-sense model of illness

6. Critically comment on the relationship between aspects and types of personality and health and illness outcomes

Define and Distinguish Health and Illness

Health

• Definition of Health:

  • "State of complete physical, mental, and social well-being and not merely the absence of disease or infirmity" (WHO, 1947)

  • Implication of Complete Health Requirement:

  • Would exclude most of the population who may be seen as unhealthy.

  • Huber (2011): Addresses the complexities of health, discussing the need for screening and treatment; a subjective perception of illness is also raised.

  • Key Questions:

    • Do we have to feel sick to feel healthy?

    • The role of stable conditions or disabilities in health perceptions.

Illness

• Definition of Illness:

  • Subjective experience of negative changes in well-being and social function.

  • Different for each individual, often leading to different definitions and responses.

Distinction Between Disease and Illness

• Disease:

  • Objective; diagnosed through pathological changes and characterized by signs and symptoms.

  • Example:

  • Hypertension is considered a disease in the absence of illness.

• Illness:

  • Subjective; characterized by personal experience and may exist even without the disease.

  • Example:

  • Phantom limb pain may exist as an illness while not being linked to a detectable disease.

Disease and Illness Interactions

• Examples of disease and illness scenarios:

  • Disease Examples: Renal failure, hypertension, skin conditions.

  • Illness Examples: Hypochondriasis.

Biopsychosocial Model of Illness

Traditional Biomedical Model

• Focuses primarily on physiological and biochemical mechanisms related to disease states.

• Pathogen exposure leads to treatment, which may or may not result in recovery, chronic states, or death.

• Referenced Work: Engel G. (1977). The need for a new medical model: a challenge for biomedicine. Science.

Modern Perspective

• The Biopsychosocial Model considers various determinants affecting health, including:

  • Physical health

  • Social context (family, culture, socio-economic status)

  • Psychological aspects (beliefs, behaviors, emotions)

  • Genetics and personal history.

• Key Components Include:

  • Psychosocial processes and the sociocultural environment have significant effects on patient health-seeking behavior.

Biopsychosocial Model Components

Levels of Analysis

• Social Level:

  • Influence of societal structures and interactions.

• Biological Level:

  • Genetic vulnerability, immune function, neurochemistry, and medication effects.

• Psychological Level:

  • Learning/memory, attitudes/beliefs, personality, coping skills, and emotions.

Comparative Analysis: Biomedical vs. Biopsychosocial Models

Model Limitations

• The biomedical model can overlook psychosocial causes and can lead to passive patient care.

Perception of Symptoms and Illness

• Influencing Factors on Health Decisions:

  • Access to treatment, expectations from treatment, personal health beliefs, personality traits, cultural context, personal history, and clinical evidence.

Individual Reactions to Symptoms

• Research Example (Stroke Awareness):

  • A study found:

  • 87% of respondents were aware of stroke symptoms through media.

  • 67% could identify multiple warning signs but only 57% would call for an ambulance.

Attention and Symptom Perception

• Individual differences in attention to internal and external symptoms:

  • Increased knowledge can amplify symptom perception (as seen in ‘mass psychogenic illness’ during COVID-19).

  • Distractions can decrease symptom perception (e.g., athletes ignoring injury).

Factors Increasing Symptom Perception Likelihood

• Consequences of Symptoms:

  • Symptoms that are painful or disrupt usual activities increase perception.

• Novelty of Symptoms:

  • New symptoms are often perceived as more serious.

• Persistence of Symptoms:

  • Chronic symptoms garner more attention.

• Pre-existing Conditions:

  • Chronic diseases lead to increased awareness of additional symptoms.

Common-Sense Model of Illness

Components of the Common-Sense Model

• Includes socio-cultural context, biological characteristics, and psychological traits.

• Key Themes in Self-Regulatory Model:

  • Identity: Labels/symptoms associated with the illness.

  • Causality: Patient beliefs about what caused their illness (e.g., heredity, lifestyle).

  • Timeline: Beliefs about the duration of illness (acute vs. chronic).

  • Consequences: Perceived immediate and long-term effects of the illness.

  • Curability/Controllability: Belief in whether a cure is possible and whether it can be controlled by self or others.

Clinical Practice Implications

• Clinicians should address factors related to illness representation in consultations:

  • Asking about the identity of the illness, perceived symptoms, causality, consequences, lengthy influences, and control factors.

Illness Representations and Outcomes

• Illness representations directly affect:

  • Seeking and adhering to medical treatment.

  • Engagement in self-care and behavior changes.

  • Quality of life and illness-related disability.

Relationship Between Personality and Health Outcomes

Big Five Theory of Personality

• The Trait Approach:

  • Considers dimensions of personality that are stable over time.

  • Eysenck posits personality is largely influenced by genetics.

  • Key dimensions include:

  • Extraversion/introversion

  • Neuroticism/emotional stability

  • Psychoticism/self-control

Evidence on Personality and Health

• Meta-synthesis of 30 meta-analyses revealed:

  • Big Five traits moderately associated with overall health ($Multiple R = 0.35$).

  • Direct Effect: Personality has a more pronounced impact on mental health.

  • Mechanisms like perceived stress mediate impacts on health behaviors and physical health outcomes.

Practical Relevance

• Understanding personality traits aids clinicians in tailoring individual medical practice, leading to potentially better health outcomes.

Conclusions

• Health and illness are complex constructs; responses to illness are highly individualized.

• The biopsychosocial model highlights that illness cannot be viewed simply as either healthy or sick; there is much variability based on individual and environmental factors.

• The common-sense model elucidates patient responses to illness, suggesting that perceptions significantly influence coping behaviors and health outcomes.

Recommended Reading

• Alder, B., Abraham, C., van Teijlingen, E., Porter, M. (2011). Psychology and Sociology Applied to Medicine. 3rd ed. Churchill Livingstone, London.

• Morrison, V., Bennett, P. (2012). An Introduction to Health Psychology. Pearson Education Limited, Harrow. 3rd ed.

• Van Der Kolk, B. (2015). The Body Keeps the Score.

• Hemingway, H & Marmot, M. (1999). Evidence based cardiology: Psychosocial factors in the aetiology and prognosis of coronary heart disease: systematic review of prospective cohort studies. BMJ, 318(7196), 1460-1467.