The World Health Organization (WHO) definition of health, established in 1948, describes health as a state of complete physical, mental, and social well-being. However, this definition is now considered outdated due to the increasing prevalence of chronic diseases. Machteld Huber and colleagues propose a shift in focus towards the ability to adapt and self-manage in the face of social, physical, and emotional challenges. The original WHO definition, while groundbreaking, has been criticized for its absoluteness, contributing to the medicalization of society and the expansion of healthcare systems. It has not been updated despite growing criticism and changing disease patterns. The definition is now seen as counterproductive, as it labels people with chronic diseases and disabilities as definitively ill, neglecting their capacity to cope and function with wellbeing. The paper discusses the limitations of the WHO definition, including its operationalization and the changing nature of diseases. It suggests a new conceptual framework for health, emphasizing the ability to adapt and self-manage. This approach considers the dynamic balance between opportunities and limitations in social, mental, and physical health domains. The new definition of health is proposed as the ability to adapt and self-manage, reflecting the dynamic nature of health. This concept is supported by examples in physical, mental, and social health domains. The paper also discusses the need for operational definitions to measure health, including tools like the COOP/Wonca Functional Health Assessment Charts. The paper concludes that redefining health as the ability to adapt and self-manage is essential for modern health policies and practices. This approach emphasizes resilience and the capacity to cope with life's challenges, supporting a more holistic and dynamic understanding of health.The World Health Organization (WHO) definition of health, established in 1948, describes health as a state of complete physical, mental, and social well-being. However, this definition is now considered outdated due to the increasing prevalence of chronic diseases. Machteld Huber and colleagues propose a shift in focus towards the ability to adapt and self-manage in the face of social, physical, and emotional challenges. The original WHO definition, while groundbreaking, has been criticized for its absoluteness, contributing to the medicalization of society and the expansion of healthcare systems. It has not been updated despite growing criticism and changing disease patterns. The definition is now seen as counterproductive, as it labels people with chronic diseases and disabilities as definitively ill, neglecting their capacity to cope and function with wellbeing. The paper discusses the limitations of the WHO definition, including its operationalization and the changing nature of diseases. It suggests a new conceptual framework for health, emphasizing the ability to adapt and self-manage. This approach considers the dynamic balance between opportunities and limitations in social, mental, and physical health domains. The new definition of health is proposed as the ability to adapt and self-manage, reflecting the dynamic nature of health. This concept is supported by examples in physical, mental, and social health domains. The paper also discusses the need for operational definitions to measure health, including tools like the COOP/Wonca Functional Health Assessment Charts. The paper concludes that redefining health as the ability to adapt and self-manage is essential for modern health policies and practices. This approach emphasizes resilience and the capacity to cope with life's challenges, supporting a more holistic and dynamic understanding of health.