In recent years, a new term often appears in popular science books, and that is “subhealth”. People often mistake “chronic fatigue syndrome” as a typical case of “sub-health” to introduce. In fact, “chronic fatigue syndrome” is a new disease named by the Centers for Disease Control in 1988, while “sub-health” does not have a strict definition in medical science. Chronic fatigue syndrome is a disease. The cause of “chronic fatigue syndrome” is still unclear, and may be related to viral infection. Because of the lack of specific laboratory tests for chronic fatigue syndrome and the many diseases and causes of fatigue, the U.S. Centers for Disease Control has specially formulated the diagnostic criteria for “chronic fatigue syndrome” to facilitate clinical diagnosis and treatment and more in-depth research. Foreign research has found that the cellular metabolism, morphological structure and physiological function of the central nervous system of patients with chronic fatigue syndrome are obviously abnormal, which is indeed a disease, not a “subhealth”. Chronic fatigue syndrome has three main types of symptoms The diagnosis of chronic fatigue syndrome is complicated. When a patient reports long-term recurrent episodes of extreme fatigue, other diseases, such as malignant tumors, autoimmune diseases, infections, endocrine diseases, etc., should be ruled out first. To confirm the diagnosis of chronic fatigue syndrome, the following basic features must be present: first, severe fatigue lasting for more than 6 months that cannot be relieved by rest; second, flu-like symptoms, including low-grade fever, muscle and joint pain, tingling or itching in the throat, swollen and tender lymph nodes in the neck or axilla, and feeling of heavy pressure in the head, with sudden onset; third, neuropsychiatric symptoms, such as memory loss, difficulty in speaking, poor concentration, comprehension Third, neuropsychiatric symptoms, such as memory loss, difficulty in speaking, concentration, poor comprehension and sleep disorders. These characteristics help to distinguish chronic fatigue syndrome from general fatigue symptoms. Chronic fatigue syndrome is often associated with depression, but it is fundamentally different from primary depression. The former is able to actively seek medical help and has hope for the future, while the latter feels lonely, hopeless and suicidal. A professional psychiatrist can distinguish them by psychophysiological indicators. Chronic fatigue syndrome is mostly seen in well-educated urban white-collar workers and may be related to heavy workload, psychological stress, unhealthy lifestyle and reduced immune function. Currently, no mortality rate has been reported for chronic fatigue syndrome. However, if the corresponding symptoms appear, you should seek medical attention in a timely manner, and you should never think of yourself as a “subhealthy state” and not care.