Herpes zoster (HZ) and postherpetic neuralgia (PHN) are relatively common diseases in dermatology clinics and pain clinics, and the incidence of herpes zoster is between 1.4 and 4.8 per 1,000 population, with a tendency to increase gradually. About 10% of patients with herpes zoster can have postherpetic neuralgia, and the incidence of postherpetic neuralgia is highest in elderly patients over 60 years of age, reaching 50%-75%. As the population ages, the incidence of herpes zoster and postherpetic neuralgia will increase significantly. The acute phase of herpes zoster is associated with pain in approximately 80% of patients, and the abnormal pain and nociceptive hypersensitivity of postherpetic neuralgia are more difficult to treat. [Pathogenesis of postherpetic neuralgia]? The pathogenesis of post-herpetic neuralgia PHN is still unclear, and according to the clinical manifestations and pathological studies during the onset of herpes zoster, it can be broadly summarized as the following three aspects. Peripheral neuropathy: The onset of herpes zoster can cause peripheral neuropathy and herpes zoster neuralgia. It was found that hyperalgesia caused by thermal stimulation was most pronounced in the most painful skin areas, and the severity of pain grading and nociceptive hypersensitivity were significantly higher in patients with nociceptive hypersensitivity to thermal stimulation, and some non-injurious stimuli (such as warmth and cold) could cause severe pain. These results suggest that there is not a simple relationship between peripheral nerve deficits and spontaneous or evoked pain, and that multiple sensory modalities may exist within the pain dermatome of patients with postherpetic neuralgia, with the initial injury receptor afferent stimulus causing a continuous connection between the peripheral nerve and the center, thus contributing to the persistent pain in postherpetic neuralgia. Other causes may also contribute to the mechanism of pain in PHN, as indicated by the good results of certain drugs applied topically to PHN, such as topical capsaicin, which is associated with substance P depletion, and topical ketamine, which is associated with noncompetitive NMDA receptors. In conclusion, postherpetic neuralgia may be caused by a combination of causes, in a manner to be further investigated. Second, central nervous abnormalities: Because one of the complications of herpes zoster is aseptic meningitis, it means that herpes zoster may involve the central nervous system while causing peripheral neuropathy. The persistence of postherpetic neuralgia despite clinical treatment of refractory postherpetic neuralgia with radiculotomy may also indicate a central cause. A comparative study of the degree of brain activity in patients with chronic pain using radioisotope PET (positron emission tomography, PET) revealed a significant decrease in thalamic activity contralateral to the affected limb in patients with pain, suggesting that altered function of the thalamus in the pain modulation loop may be an important It is believed that the altered function of the thalamus in the pain modulation loop may be an important cause of chronic pain. Some psychiatric symptoms, one of the complications of herpes zoster, can always accompany postherpetic neuralgia, such as 25% of patients with insomnia, 20% with mental distress (helplessness and frustration); more elderly patients older than 50 years old with insomnia, accounting for 30%, significantly more than younger patients under 40 years old. soldlovics tajic reported a case of elderly postherpetic neuralgia PHN patient with severe mental depression and no previous psychiatric or family history, suggesting that psychiatric treatment is necessary for patients with postherpetic neuralgia. Whether psychiatric symptoms are related to central neuropathy needs further study. Some pain symptoms may be directly related to the mental state [clinical manifestations of postherpetic neuralgia] Postherpetic neuralgia is mostly seen in people with low immunity and old and frail bodies. When the ophthalmic branch of the trigeminal nerve (fifth cerebral nerve) is involved, it can involve the cornea and affect vision; invasion of the facial nerve (seventh cerebral nerve) and the auditory nerve (eighth cerebral nerve) can lead to facial paralysis and auditory symptoms; in the sacral region (S3 neuron), it can cause neurogenic bladder, resulting in difficulty in urination or drowning, etc., but it can be recovered. Some patients are afraid to wear clothes in order to reduce clothing irritation, and some patients also hold up their clothes from time to time in order to avoid painful attacks caused by clothing irritation. This pain hypersensitivity reaction, some of them also show spontaneous pain, no thing touching the affected part also often occur pain. Some patients suffer a lot of mental and psychological damage because of the pain, even if they can’t eat and sleep at night. Other patients are emotionally overwhelmed by chronic pain, and some are depressed and desperate. The treatment of post-herpetic neuralgia】 At present, Western medicine at home and abroad believes that it is extremely difficult to completely restore the pain and sensory abnormalities of post-herpetic neuralgia patients to normal. To date, a large number of various therapies have been tried for postherpetic neuralgia, but a decisive and long-term curative treatment has not been found. The treatment of refractory postherpetic neuralgia mainly focuses on relieving pain, improving sleep, and improving the quality of life. I. Oral medication: At present, oral administration is still the preferred method of treatment for postherpetic neuralgia PHN. Drug therapy mainly includes: non-steroidal anti-inflammatory analgesics, opioids (extended release), antidepressants, antiepileptics, sedatives, etc. Second, nerve block: In the early stage of postherpetic neuralgia, nerve block has a certain effect. Stellate nerve block, epidural block, paravertebral nerve block and nerve trunk block can be applied according to the innervation of the pain site. It has been reported that within 3 months after the onset of herpes zoster, 70%-80% of patients with sympathetic nerve block can have their pain reduced, but the effect of nerve block is significantly reduced in patients with refractory postherpetic neuralgia of longer duration. Nerve destruction therapy; for patients with refractory postherpetic neuralgia, nerve destruction can be used when the effect of various methods is not good or cannot be maintained to achieve a longer-term effect. Ethanol and phenol glycerin are commonly used nerve-disrupting drugs as well as corresponding nerve root and ganglion disruption treatments. In conclusion, early recognition of postherpetic neuralgia is very important, as postherpetic neuralgia becomes a refractory disease once it has been diagnosed for more than 6 months. Patients and their families must be well prepared. Western medicine believes that it is very difficult to completely eliminate the pain of postherpetic neuralgia, therefore, early selection of Chinese and Western medical treatments that seek to treat the root of the disease not only has a greater advantage in reducing the unbearable pain of patients, but also has no adverse side effects.