What is pain? Pain is an innate sensation. Newborns are born with pain sensation, and even fetuses are born with pain sensation in the mother’s body. Pain is a protective function given by God, so the medical profession has always used pain as a warning sign to avoid harm. However, prolonged pain is often counterproductive, and it has lost its function as a warning sign. Chronic pain has a great impact on human physiology, psychology, and life functions. Pain can turn a brave man into a coward; make a wise man lose his ability to think; make a man lose his will to live because of this torture. Pain increases the heart rate and blood pressure, and increases the load on the heart. Pain accelerates breathing and increases the consumption of oxygen in the body. Pain increases metabolic effects and even causes nitrogen and endocrine imbalance. Pain causes suppression of gastrointestinal functions, resulting in poor appetite and indigestion. Pain can inhibit the desire and function of reproductive organs. Pain also makes people anxious, worried, withdrawn, and irritable, causing tension and deterioration in interpersonal relationships. Patients with chronic pain are often unable to work normally, which can lead to personal and family financial ruin. Since chronic pain is now treated as a long-term condition, the medical profession has felt the need to train a group of specialists to treat these patients, which led to the establishment of a subspecialty in anesthesia in the United States in 1993 and government recognition of a pain management subspecialty. Currently, only 60% of pain physicians in the United States are anesthesiologists, while the other 40% are in various disciplines. Pain departments have been established in various countries around the world with different mechanisms. What exactly does a pain department do? This is a frequently heard question, and because it is a new discipline, the positioning of pain medicine is not easy and varies from country to country. The basic functions of pain medicine are: 1) to promote basic research on pain, because although pain is a well-known topic, there are still too many areas that are not understood by the medical profession; 2) to make a complete and detailed examination of the patient’s pain, and to make a correct diagnosis of the patient’s pain; 3) to have an in-depth understanding of the neurophysiology and psychology of pain, and to have the knowledge of general medicine; 4) to treat patients suffering from pain with love and patience. 5. have the ability to read radiological data, general medical examination, electrophysiological examination, and psychological test data; 6. have an in-depth understanding of the clinical pharmacology of pain-related drugs in order to “master” the use of pain management drugs; 7. perform various new pain treatment techniques. The establishment (or survival) of a specialty must be “superior” or it will be eliminated. A pain physician must have the ability to diagnose and administer medications for pain, and to master the minimally invasive interventional pain management techniques that are currently in vogue. For example, a patient with shingles usually goes to a dermatologist for a painful blister on the skin, and after a week or two of acyclovir, skin creams and pain medication, unfortunately 10% of the patients will have persistent pain or post-herpetic neuralgia after the herpes has crusted over. The dermatologist will refer the patient to a neurologist. If the pain continues after the neurologist has given the usual painkillers and neurotropics, the patient will seek medical help from various sources, including Chinese medicine, acupuncture, cupping, bloodletting, herbal medicine, and various prescriptions and remedies available on the market, but if they are still ineffective, the patient will be at a loss. The cause of this patient’s illness is very clear, it belongs to the destruction of the nerves by the herpes virus causing imbalance and sensitization of the peripheral and central nerve conduction, the pain he or she suffers from does not have any warning value, but is completely consumed by this pain day and night, resulting in “painful”, physical and mental collapse, this patient is in need of a pain specialist to relieve or alleviate his pain with a variety of analgesic therapy, in order to have a quality of life. In another example, a patient with colon cancer was found to have metastasis to the thoracic spine and severe pain on the nerves a few months after the surgical resection. The patient’s cause was clear, and the pain was of little value. The general surgeon, orthopedic surgeon, and neurosurgeon all said there was no surgery available, and the neurologist had no prescription. But nowadays, pain doctors are able to provide effective analgesic therapy so that these patients can live their last days with their families without pain or minimal pain. With the development of the economy and the awareness of human rights, both the public and the medical profession are convinced that long-term pain needs to be handled by a specialist, just as diabetes requires a specialist in metabolism, rheumatoid arthritis requires a specialist in rheumatology …… and so on. Although pain medicine is still in its infancy (it has only been established in the United States for about 10 years), its existence will be accepted by the medical community in time.