Introduction
This topic defines health and disease and the main categories used in pathology to describe a disease: its cause, mechanism, structural changes, healing and dying.
Health and disease
- Health - a sustainable dynamic equilibrium of the organism with the environment, through which the correlation between structure and function allows the body to realise its biological potential (reach its full potential).
- Disease - something that disturbs this equilibrium and changes normal functions. Outcomes: recovery, death or a chronic course.
- Disease is also defined as an expression of discomfort due to structural or functional abnormality. It can be inflammatory, acute or chronic, congenital or acquired, genetic or environmental, and mild, moderate or severe.
- Disease has four aspects: etiology (causal agent), pathogenesis (mechanism of change), morphology (structural change) and clinical expression.
- Example, tuberculosis: etiology - Mycobacterium tuberculosis; pathogenesis - cell-mediated (type IV) hypersensitivity; morphology - caseating granulomas with Langhans giant cells; clinical expression - chronic cough, haemoptysis, night sweats and weight loss.