Concepts of disease and causation HEALTH Concepts of

Concepts of disease and causation

HEALTH • Concepts of health – 1. Biomedical concept – 2. Ecological concept – 3. Psychological concept – 4. Holistic concept • WHO definition of health: – Health is a state of complete physical, mental and social wellbeing and not merely an absence of a disease or infirmity.

Concept of disease • Define health • Disease ? – Departure from state of health, an alteration of the human body interrupting the performance of vital functions Webster – Condition of a body or some part or organ of the body in which functions are disrupted Oxford dictionary – Ecological – maladjustment to environment – Sociology – looking at disease from a society point of view

Concept of disease • Simplest defn: opposite of health • But all are inadequate as they cannot specifically pin point as to where the disease process started • Disease has a spectrum ranging from in apparent infection to severe manifestation to death

Some important concepts • Disease – Physiological or psychological dysfunction • Illness – Subjective state of person feeling unwell • Sickness – State of social dysfunction

Causation of a disease

Theories of disease causation • Supernatural theory • Theory of humors • Concept of contagion • Miasmatic theory of disease • Theory of spontaneous generation

Germ theory of disease Disease Agent Man Disease

Epidemiological Triad ENVIRONMENT AGENT HOST

Triangle of Epidemiology ENVIRONMENT TIME AGENT HOST

Advanced Model Of Epidemiological Triad Causative factor TIME Groups Environment behaviour & culture

Web of causation

Web of causation

Web of causation

Web of causation

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