Introduction: Well-being, as a key concept in welfare and social policy, has become theoretically and politically more important in academic and policy making contexts in recent decades. However, there is no comprehensive and established definition for this concept, and thus reaching a clear definition is essential for creating a conceptual framework and for measuring well-being.

  Method: The present review article is based on a critical and constructive analysis of previous works on different concepts and definitions of wellbeing. Literature reviews showed that there is no acceptable theoretical and operational definition of well-being. In other words, wellbeing is a complex, multidimensional and multidisciplinary concept which leads to numerous different definitions with overlapping or sometimes contradictory meanings.

  Discussion: After a critical review of different perspectives of wellbeing, from objective to subjective and hedonic to eudemonic approaches, in this article we propose a new definition of well-being as follows: “Wellbeing is a desirable situation which becomes meaningful when considered within social, economic, political and environmental contexts. It is a dynamic situation within which an individual consistently has a dialogue between his/her inner self and the external environment. Perceiving an imbalance between the inner self and the external environment and also lack of coordination of external factors disrupts the desirable situation of the individual. It is also a process stemming from accumulation of the individual experiences through different stages of life: childhood, youth, adulthood, middle-age, and old age.”