Based on the pathogenesis of pain, chronic pain can be divided into injurious or inflammatory pain (appropriate response to painful stimuli) and neurogenic pain (inappropriate response induced by damage to the nervous system). The International Association for the Study of Pain (IASP, 1994) defines neurogenic pain as “pain caused by primary or secondary damage or dysfunction or transient disturbance of the peripheral or central nervous system”; neuropathic pain is defined as “pain that is caused by a primary or secondary damage or dysfunction or transient disturbance of the peripheral or central nervous system”. In January 2011, PAIN, the official academic journal of IASP, published the article “Outline of NeuPSIG neuropathic pain evaluation” signed by 21 institutions, and clearly defined the new definition of neuropathic pain. The definition of neuropathic pain is translated as pain directly caused by injury or disease of the somatosensory nervous system. Neuropathic pain has always been a difficult problem for the medical community: the pathogenesis is unclear, opioid therapy is ineffective, and patients are in great pain. In recent years, with the development of molecular biology and electrophysiological techniques, the complex pathological mechanisms of neuropathic pain have been gradually recognized in depth and provide new ideas and methods for treatment. Characteristics Symptoms unrelated to stimulation (described by the patient) 1. spontaneous pain (aggravated at rest especially at night): persistent burning pain, intermittent stabbing pain, electric shock-like, throbbing pain, etc. 2, abnormal sensation: abnormal sensation on the skin without objective cause: anthroposis. 3.Sensory dullness: pain in the numb area of the skin Stimulus-related (stimulus-induced) 1.Nociceptive hypersensitivity (Allodynia)-pain to normal painless stimuli 2.Nociceptive hyperalgesia (Hyperalgesia)-increased response to painful stimuli or persistent severe pain. The above symptoms may improve during activity or when cold compresses are applied, and may worsen after activity or exertion; the symptoms worsen at rest, especially at night.