Abstract: It has been more than two decades since the advent of burgeoning research interest in “sub-health” in China. The concept of “sub-health” has been widely accepted and has even entered public discourses, but the definition, diagnosis, and psychopathological mechanism of “sub-health” remain unclear. Currently there is no internationally recognized equivalence for the term “sub-health”. It is thus urgent to identify the risk factors contributing to sub-health so that they can be applied in the clinical prevention, screening and intervention. Beginning with the concept of “risk factors,” and following the “diathesis-stress” model, the authors distinguish “risk signals” from other kinds of risk factors, and incorporated psychology risk factors into a model of “vulnerable diathesis-risk stress-psychological risk signals”. Using this model as a conceptual framework, the authors review the research development in the following three areas: psychologically vulnerable diathesis of cognition, personality and trauma residual stress; risk stress; and risk signals of mood and behavior. This article explicates the psychological mechanisms of sub-health, and emphasizes the importance of psychological approach in preventing and intervening with sub-health. Future directions of the research on sub-health are also discussed.

Key words: sub-health, psychological risk factors, vulnerable diathesis, stress, risk signals