Health is a complex, multidimensional concept. It can be understood in terms of a person’s ability to function, to cope with and thrive despite life challenges, and to live a meaningful and fulfilling existence. Health is also a system of interconnected relationships between the individual, their environment, and their internal state.
Consequently, many different definitions have been advanced. Some focus on the control people have over their lives (and, by extension, their quality of life), while others prioritize a person’s ability to realise their expectations and meet their needs. Still others emphasize sustainability, with the idea that a healthy society is dependent on a sustainable world.
All of these perspectives have merit, but none is without limitations. For example, a definition that emphasises control is likely to obscure the social determinants of health and can perpetuate inequalities. On the other hand, a definition that only considers capacity risks reducing health to a mere economic commodity.
A definition of health should be able to accommodate the complexity of reality while providing a framework for improving and measuring the status of a population’s health. In this regard, the WHO’s 1948 definition of health is a good starting point. It defines a state of “complete physical, mental and social well-being and not merely the absence of disease or infirmity.”
This definition provides room to consider the relationship between an individual’s lifestyle choices and their resulting health outcomes, while acknowledging that an absolute definition of health is unobtainable. As we move into an era of new discoveries about how diseases work at molecular levels and the influence of environmental factors, this is a particularly important consideration.
It also allows for the recognition of health inequalities – systematic, avoidable and unfair differences in health outcomes that can be observed between groups within a society or as a gradient across populations ranked by their social position. This feature of a definition of health is often missing from current proposals but it is essential to recognise the need for political attention and action in relation to the health of individuals and communities.
As we approach 2020 and the end of the COVID-19 pandemic, it is appropriate to reflect on how the concept of health should be framed in the future. The definition that is offered here combines the best features of those previously advanced. It is dynamic, fluid, and multidimensional. It is distinct from limitations, but it includes a dimension that can connect an individual with their sense of purpose and meaning in life. It is a definition of health that can help us make informed decisions about what matters most for human health and the achievement of a meaningful, equitable society. The authors wish to thank the WHO Collaborating Centre for Development Research and Innovation in Health and the WHO’s Commission on Disability and Development for their assistance in developing this paper. We would also like to acknowledge the contribution of all the contributors. This article was developed from an earlier version published in the WHO Bulletin.