Health, Definitions of

Epidemiology is often defined as the study of the occurrence and determinants of disease in human populations. Another way to look at epidemiology is to define it as the study of the health of human populations, which requires a definition of what is meant by health. The definition of what constitutes health is partly dependent on culture and historical period, so this entry concentrates on two general ways of conceptualizing health that are in common use today in the industrialized world: the medical model and the holistic model.

The medical model defines health as the absence of disease or injury, so a healthy person is one who is not suffering from a disease or injury as defined by current medical practice. This model was common in the industrialized world in the 20th century and is still common in the medical profession. It places an emphasis on treating and curing diseases and injuries after they occur, and it does not focus on prevention. This model also emphasizes diseases that have clearly observable signs and symptoms and that can be treated or cured, and it often places greater weight on physical rather than mental disease and on curing acute diseases rather than enhancing the quality of life of those with chronic diseases.

[Page 459]The holistic model is more commonly used in public health. Those advocating this model often cite the definition of health included in the Preamble to the Constitution of the World Health Organization (WHO), which was adopted in 1946 and entered into force in 1948. The Preamble defined health as ‘a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity’ and further stated that ‘the enjoyment of the highest attainable standard of health’ was a fundamental right of every human being (WHO Constitution; unpaginated). Health as a human right was a new concept when this statement was first made, but it has become accepted as a goal if not a reality by many people working in public health.

The WHO definition has been criticized as being both utopian and unmeasurable: Critics point out that every unfortunate aspect of human life, from warfare to religious oppression, could be considered within the scope of ‘health’ by this definition, and further that with so inclusive a definition, the terms loses its meaning because hardly anyone could actually be considered to be healthy. Supporters of the holistic definition counter that many nonmedical aspects of life affect health, and that beginning with a broad rather than narrow model allows consideration of many threats to health, while requiring sound judgment as to which are the highest priority for intervention.