Regarding the diagnosis of CFS. Diagnostic criteria were developed in 1988 in the United States and Australia, 1991 in the United Kingdom, and 1993 in Japan, but they all differed to some extent. Until 1994, the United States revised and improved the diagnostic criteria of CFS, which is recognized as the gold standard by the international medical community, and its content includes the following three aspects: 1. Continuous or recurrent severe fatigue of unknown origin, with a medical history of not less than 6 months: this fatigue is not caused by being engaged in labor, and cannot be relieved by rest, and the patient’s occupational ability, educational ability, activity ability and personal life are substantially lower than those before the disease. There is a substantial decrease in the patient’s occupational ability, educational ability, activity ability and personal life compared with those before the disease. 2. At least 4 of the following 8 items are present at the same time: (1) Significant decrease in memory or concentration; (2) Sore throat; (3) Swollen and tender lymph nodes in the neck or axilla; (4) Muscle pain; (5) Multiple joint pain without redness or swelling; (6) Recurrent headaches; (7) Poor sleep quality. (8) Lethargy lasting 24 hours after light labor. (3) Exclude the following chronic fatigue: (1) chronic fatigue that can be explained by the cause of the original disease; (2) chronic fatigue caused by some diseases that are clinically diagnosed, but difficult to treat under the existing medical conditions. Social development and medical advances have led to the inclusion of “fatigue” in the category of diseases. However, not all fatigue manifestations are pathological, only excessive and prolonged fatigue, i.e. chronic fatigue, can be called a disease and needs to be taken seriously and treated. This scale is more difficult to define in clinical diagnosis. If similar symptoms of CFS occur, one should go to the hospital for examination in all aspects, both physically and psychologically, rather than jumping to a conclusion about CFS.