A systemic review of suboptimal health

The "suboptimal health" is a term used to describe a group of conditions that affect many people around the globe but cannot be diagnosed with any diseases of clinical standards. Due to the complexity in conditions and manifestations, there have been controversies about how to define and categorize the suboptimal health. In this paper, we thoroughly analyzed the currently available suboptimal health research articles and discussed the related issues about the concept of suboptimal health and the diagnostic criteria. The differential diagnosis between chronic fatigue syndrome and psychosomatic diseases was made. The problems in suboptimal health research and future directions were solved.