The extent to which an individual or a group is able to realize aspirations and satisfy needs, and to change or cope with the environment. Health is a resource for everyday life, not the objective of living; it is a positive concept, emphasizing social and personal resources as well as physical capabilities.

A state characterized by anatomic, physiologic, and psychological integrity; the ability to perform personally valued family, work, and community roles; the ability to deal with physical, biologic, psychological, and social stress; a feeling of well-being; and freedom from the risk of disease and untimely death.

A state of equilibrium between humans and the physical, biologic, and social environment, compatible with full functional activity.

World Health Organization. Definitions. Internet. Accessed August 7, 2009.

The World Health Organization defined health in its broader sense in its 1948 constitution as “a complete state of physical, mental, and social well-being, and not merely the absence of disease or infirmity.” This definition has been subject to controversy, in particular as lacking operational value because the use of the word "complete."

Other definitions have been proposed, among them a definition developed by Indigenous Australians that correlates health and personal satisfaction “…Health does not just mean the physical well-being of the individual but refers to the social, emotional, spiritual, and cultural well-being of the whole community. This is a whole of life view and includes the cyclical concept of life-death-life."

Adapted from World Health Organization. Bulletin of the World Health Organization. Re-defining "Health." 2015.