What is Health?

Defining health sounds easy. However, depending upon who is doing the defining and in what context, 'health' can take different meanings. As the idea of 'population health' has become more influential over the last decade, ‘health’ no longer merely refers to the sum of the health of individuals.

The World Health Organisation (WHO)’s definition of health is among the more comprehensive definitions and is widely known. According to WHO [1] health is:

‘A state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.’

This definition is attractive, because it does not define health as an absence of disease or through negative references. It is important to remember, however, that it has met with some criticism and is not adopted by all healthcare systems.

Health system decision makers generally measure health and the performance of health systems in terms of goodness and fairness:

• Goodness means a health system responding well to what people expect of it (achieving the best attainable average level of health for the overall population).
• Fairness means it responds equally well to everyone, without discrimination (achieving the smallest feasible differences in health between individuals and groups).