Many healthcare systems are facing crises of excess demand, increased prevalence of chronic disease, spiralling costs, and workforce challenges which threaten their functioning.12 Recent evidence suggests that part of the increase in prevalence of “disease” is due to overdiagnosis, overtreatment, and overall low value care.3 It has been estimated that 30% of medical care is of low value or wastes resources, and 10% is harmful.4 The health sector is estimated to account for more than 5% of greenhouse gas emissions in industrialised countries—another way in which low value care threatens health.5

There is a need for more capacity in healthcare, more investment in healthcare, and more staffing in some regions, and for specialties to improve health, wellbeing, and inequality. However, the exponential expansion of medical territory in the last half century has become unsustainable, leading to soaring healthcare costs, an unreasonable treatment burden for patients, burnout among healthcare staff, and substantial harm to the planet. We need further thought and discussion about the finite financial, human, societal, and planetary resources available for healthcare and about better distribution of existing resources.

Current crises in healthcare delivery are exacerbated by ageing populations and associated multimorbidity. Policy makers, politicians, and the public need to understand how even well-meaning efforts to provide more and better healthcare inevitably amplify and reinforce these crises through overdiagnosis, overmedicalisation, and overtreatment, diverting resources from more effective options.6 These issues must be resolved if we are to achieve sustainable healthcare.

Being open to the possibility of excess healthcare, watching for the signs, and taking action to reduce it, will help ensure that all diagnostic labels are meaningful and that tests and treatments confer clinically relevant benefits. It will also help decision makers to invest their time and resources in high value healthcare, rather than on uncertain or harmful screening, technology, products, or interventions.