Pain is a perceptual experience produced by an injurious stimulus acting on a certain part of the organism, which enters the field of consciousness through the transmission of the nervous system. Pain is different from primitive sensations such as touch, pressure, cold, and warmth; it is often accompanied by unpleasant emotions; it often coexists with other sensations and constitutes a compound sensation; it often has subjective experiential properties; and pain is the most prevalent and important symptom in disease. Pain is a signal that the organism is being harmed and can elicit an active or passive defensive response that facilitates the adaptation of the organism to its environment; however, it also causes distress and produces adverse psychosomatic effects and even serious consequences (e.g., suicidal ideation). Although pain is usually considered organic, there are some types of pain that are caused by psychological factors, called “psychogenic pain”. The response to pain is also strongly influenced by psychological state and varies from person to person, from time to time, and from place to place. Pain can only be described by the individual’s own experience and is difficult to measure objectively. ”Pain is the earliest and most experienced subjective sensation in a person’s life, and is the main signal of damage to human tissues and organs. It serves as a protective signal to avoid danger or to see a doctor. For chronic pain that is still tolerable, many people do not take it seriously and tolerate it as long as they can. In fact, pain not only causes mental anguish, loss of labor force, and loss of quality of life, but also causes disorders in the function of various organs and systems of the body and low immunity, which can lead to various complications and greatly shorten the life span of a person. The Department of Pain Medicine is the specialized department to solve various chronic pains, and chronic pain diseases should be promptly treated in the relevant departments.