First, a distinction should be made between “normal” and “abnormal” pain. Healthy individuals may experience pain thousands of times in their daily sensory experience. Examples include more persistent dull aches in the muscular neck, shoulders, and lower legs, and sharp pains in the arms and legs. This so-called “normal” pain can occur at any age, is short-lived, and generally does not require treatment. Only when the intensity and duration of the pain and the occasions of its occurrence have become part of the disease, or even the main clinical manifestations, is it necessary to find out its etiology and pathogenesis. First of all, let the patient describe the information about his pain in detail and ask appropriate questions. Diagnosis of the general rules a. The site of pain by the superficial damage to the pain, the cause is often obvious. If the pain is caused by the deep structure of the body or internal organs, the patient often describes the pain as the spinal cord segments of the corresponding body part of the ambiguous pain. For example, if there is epigastric or subxiphoid pain or back pain, one should look for lesions in the structures innervated by the T6-8 spinal cord segments, including the esophagus, stomach, duodenum, bile ducts, retroperitoneal structures, and the deep tissues of the body in these areas; and one should also consider the possibility of lesions in the organs innervated by the T6 or T8 segments. Factors contributing to and relieving pain Pain associated with breathing, swallowing, and defecation should be thought of as a lesion of the respiratory tract, esophagus, and lower gastrointestinal tract; pain that begins a few minutes after activity and is relieved by rest suggests ischemic and neurologic mechanisms. Pain that occurs a few hours after eating and is relieved by food or alkalizing agents suggests irritation of the gastric and duodenal mucosa. Pain that is induced or relieved by some kind of movement or position is a disease of the locomotor system (bones, muscles, ligaments). Pain aggravated by coughing, sneezing, and exertion often originates from nerve roots or ligamentous structures. Third, the nature of pain, time and intensity of the characteristics of the best is to let the patient themselves to choose the appropriate words to describe the nature and intensity of their pain and so on. Fourth, pain onset formation pain intensity peaks almost immediately after onset, suggesting tissue rupture. The pain of rupture of intermural aortic aneurysm is an example of this, the pain is sudden and severe, and reaches its peak in a few seconds or minutes, which can sometimes be differentiated from chest pain due to myocardial infarction. Perforation of ulcer disease can sometimes lead to similar pain episodes. The duration of angina is rarely shorter than 2-3min, and may be longer than 10-15min. ulcer pain can last from 1 to several hours, unless relieved by medication or food. Six, the time of the onset of pain, which is very important for patients with transient pain, because it can be accurately timed. Such as ulcer disease patient’s pain and its previous meal between the interval. Arthritis pain is often obvious when the patient starts to move after a long period of inactivity. Pain in metastatic cancer of the bone tends to be worse at night. The above features of pain should be considered together in order to determine the site and pathogenesis of the lesion. One should think about what causes pain and what makes pain relief, etc. The accuracy of the information we collect depends on our skill in asking questions and the ability of the patient who answers them to observe, remember and express themselves. It is not possible to devise a fixed set of questions to address all pain management. It is important for the physician to ask questions based on the patient’s complaints, which will provide key clues to the management of pain. The general principles of treatment of pain are to make a clear diagnosis and remove the cause as much as possible; to raise the pain threshold; to slow down the nerve conduction velocity, including the treatment of certain nerve mediators related to the conduction of pain; and to minimize or even eliminate the effect of pain stimuli on pain receptors. Non-narcotic analgesics are effective in treating peripheral pain (originating from the skin, bones, muscles and joints) and can relieve pain without affecting consciousness. (b) Mechanism of action Prostaglandins stimulate injury-receptive nerve endings and cause pain. Salicylic acid and other non-steroidal anti-inflammatory drugs inhibit the synthesis of prostaglandins and have an analgesic effect, but they have no effect on other injurious, pain-conducting neuromediators, such as bradykinin and histamine. (iii) Preparations and Usage Aspirin, 300-600mg per session, every 4-6h, or acetaminophen (Tylenol), 650mg per session, every 4-6h, or finasteride, 600mg per session, every 3-4h, may be used. These three ingredients in different proportions, or add caffeine, that is, commercially available painkillers. (d) Side effects All non-steroidal anti-inflammatory drugs have side effects such as gastrointestinal irritation and allergic reactions. Ethacrynic acid is not indigestion, gastrointestinal bleeding and platelet aggregation inhibition and other side effects of aspirin, so it is safer; and in many cases more effective. (e) Drug interactions The pain-relieving effect of aspirin and ethacrynic acid combined is not stronger than that of ethacrynic acid alone. However, when either is combined with codeine, it is more effective than codeine alone. Second, mild anesthetics if the above drug treatment is ineffective, it is necessary to urgently use (5-7 days) mild anesthetics, such as codeine, oxycodone (Oxycodone). Their pain-relieving effect is slightly better, but there is a risk of addiction in the short term. Myocardial infarction, pulmonary infarction, biliary colic and renal colic often require more effective anesthetics. Third, the treatment of pain in the central and peripheral nervous system damage can cause severe pain that is not easy to control, such as thalamic syndrome, burning neuralgia, phantom limb pain and postherpetic neuralgia. The mechanism of these severe pains is due to the loss of normal inhibition of nociceptive conduction and sensation, or due to the formation of abnormal excitation in the central conduction pathway. In recent years, research has begun on strengthening the inhibition of nociceptive conduction pathways to treat malignant pain. Strong stimulation of crude fibers reduces pain. Stimulating the nerve for 2 to 3 min with a unidirectional wave whose voltage does not cause motor effects or pain proximal to the injury in patients with burning neuralgia can provide pain relief. Inject 10% saline into the lumbar interspinous ligament of the lower limb phantom limb pain patients, in the occurrence of radiating pain involving the normal side of the lower limb at the same time, the phantom limb gradually appeared to be numb and the pain is discontinued, which can last for 24~36 h. Repeated injections are effective.