BMJ 2011; 343:d4163 doi: 10.1136/bmj.d4163 (Published 26 July 2011) Cite this as: MJ 2011; 343:d4163

How should we define health?


The WHO definition of health as complete wellbeing is no longer fit for purpose given the rise of chronic disease. Machteld Huber and colleagues propose changing the emphasis towards the ability to adapt and self manage in the face of social, physical, and emotional challenges
The current WHO definition of health, formulated in 1948, describes health as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.”1 At that time this formulation was groundbreaking because of its breadth and ambition. It overcame the negative definition of health as absence of disease and included the physical, mental, and social domains. Although the definition has been criticised over the past 60 years, it has never been adapted. Criticism is now intensifying,2 3 4 5 and as populations age and the pattern of illnesses changes the definition may even be counterproductive. The paper summarises the limitations of the WHO definition and describes the proposals for making it more useful that were developed at a conference of international health experts held in the Netherlands.6

Limitations of WHO definition
Most criticism of the WHO definition concerns the absoluteness of the word “complete” in relation to wellbeing. The first problem is that it unintentionally contributes to the medicalisation of society. The requirement for complete health “would leave most of us unhealthy most of the time.”4 It therefore supports the tendencies of the medical technology and drug industries, in association with professional organisations, to redefine diseases, expanding the scope of the healthcare system. New screening technologies detect abnormalities at levels that might never cause illness and pharmaceutical companies produce drugs for “conditions” not previously defined as health problems. Thresholds for intervention tend to be lowered—for example, with blood pressure, lipids, and sugar. The persistent emphasis on complete physical wellbeing could lead to large groups of people becoming eligible for screening or for expensive interventions even when only one person might benefit, and it might result in higher levels of medical dependency and risk.
The second problem is that since 1948 the demography of populations and the nature of disease have changed considerably. In 1948 acute diseases presented the main burden of illness and chronic diseases led to early death. In that context WHO articulated a helpful ambition. Disease patterns have changed, with public health measures such as improved nutrition, hygiene, and sanitation and more powerful healthcare interventions. The number of people living with chronic diseases for decades is increasing worldwide; even in the slums of India the mortality pattern is increasingly burdened by chronic diseases.7
Ageing with chronic illnesses has become the norm, and chronic diseases account for most of the expenditures of the healthcare system, putting pressure on its sustainability. In this context the WHO definition becomes counterproductive as it declares people with chronic diseases and disabilities definitively ill. It minimises the role of the human capacity to cope autonomously with life’s ever changing physical, emotional, and social challenges and to function with fulfilment and a feeling of wellbeing with a chronic disease or disability.
The third problem is the operationalisation of the definition. WHO has developed several systems to classify diseases and describe aspects of health, disability, functioning, and quality of life. Yet because of the reference to a complete state, the definition remains “impracticable, because ‘complete’ is neither operational nor measurable.”3 4