The concept, common clinical manifestations and diagnostic criteria of sub-health are clearly expounded from the perspective of traditional Chinese medicine, which has a wide influence. Many scholars in China have put forward evaluation methods or diagnostic criteria for sub-health. The Clinical Guide of Sub-health Chinese Medicine issued by China Society of Traditional Chinese Medicine points out that sub-health refers to a state between health and disease.
People in sub-health state can't meet the health standards, which are manifested as the decline of vitality, function and adaptability in a certain period of time, but they don't meet the clinical or subclinical diagnostic standards of modern medicine. The main reasons leading to sub-health are: unreasonable diet, lack of exercise, irregular work and rest, lack of sleep, mental stress, great psychological pressure, long-term bad mood and so on.
Domestic research on sub-health is mostly limited to cross-sectional surveys, and most of the tools used are self-rating scales or questionnaires. These surveys involve teachers, civil servants, enterprise personnel, community residents, medical staff and other different groups. Due to different definitions of sub-health and different questionnaires or scales, the detection rate of sub-health reported in various studies is also quite different, mostly between 20% and 80%.