1.What is sudden deafness? Sudden deafness is a sudden onset of sensorineural hearing loss, characterized by significant hearing loss within minutes, hours or 3 days. It is characterized by a significant hearing loss within minutes, hours or 3 days. It is usually unilateral in onset, but occasionally both ears are affected simultaneously or sequentially. 2. How is sudden deafness caused? The etiology of sudden deafness is unknown, and many causative factors may cause sudden deafness. The main theories that have been widely recognized are as follows: Viral infection theory: It may be an acute inflammation of the inner ear caused by a virus, and many patients have a history of upper sensory disease before the onset of the disease. Vascular embolism and circulatory disorders theory: The blood supply to the inner ear comes from the vagus artery, and the physiological activity of inner ear hair cells consumes high amounts of oxygen and is poorly tolerant to hypoxia, and microcirculatory dysfunction of the cochlea caused by various reasons can cause damage to the function of the auditory organ and cause hearing loss. In addition, there are autoimmune theory and membrane vagus rupture theory. 3.How to diagnose and treat sudden deafness? Idiopathic sudden deafness should be diagnosed only after a clear cause of sensorineural deafness has been excluded. Once the diagnosis of sudden deafness is confirmed, the timeliness of its treatment is important; the earlier the treatment, the greater the possibility of recovery, and generally the treatment within a week is of greater value. Intravenous medication is the preferred treatment. It can also be combined with hyperbaric oxygen therapy.