Sudden deafness, also known as “idiopathic deafness”, is a sudden onset of sensorineural deafness, referred to as violent deafness or sudden deafness. This type of deafness is relatively common, and the cause can be found quickly in some cases, while in others the cause is not found for a long time. It is often unilateral or, in some cases, bilateral. The main symptom is deafness of varying severity, sometimes accompanied by vertigo and tinnitus of varying degrees. In severe cases, there is nausea, vomiting and nystagmus. The hearing curve of the affected ear can be roughly divided into four types, namely high frequency deafness, low frequency deafness, flat type and total deafness. The cause of sudden deafness is not very clear and is mainly related to the following conditions. Many viruses can cause sudden deafness, and many patients have a history of colds before the onset of the disease, especially in young people. For example, mumps virus, cytomegalovirus, herpes virus, varicella-zoster virus. 2, vascular lesions Currently, for flat and high frequency descending sudden deafness is thought to be related to the blood vessels supplying the inner ear. 3. Systemic immune and metabolic diseases Many systemic immune diseases can cause sudden deafness, especially low-frequency sudden deafness, which is related to inner ear edema, and the effect of immunotherapy is obvious. In addition, there is a high incidence of sudden deafness in diabetic patients, which is associated with abnormal systemic glucose metabolism and impaired microangiopathy.