What is health?

Health is a term that is widely used (for example, in the title of this symposium) but the underlying assumption that readers share a common understanding of its meaning is rarely justified (Seedhouse, 1986). Before the validity of health measurements can be discussed, the meaning of health must be clarified. A useful starting point is the definition of health included in the charter of the World Health Organization (WHO, 1946): ‘Health is a state of complete physical, mental and social well being and not merely the absence of disease or physical infirmity’.

As a statement of ideals it cannot be faulted, but it is doubtful that it describes an attainable goal and it does not offer a useful basis for measurement. A different definition is ‘Health is a state in which a person is enabled to work to fulfil their realistic chosen and biological potential’ (Seedhouse, 1986). From a practical point, this is much to be preferred, recognizing as it does that different individuals have different potentials. However, for purposes of measurement, it complicates things even further requiring not only the present state of each individual to be assessed but also their theoretical potential.

None the less, three important characteristics of health emerge from these definitions: