There is a clinical condition of hearing loss called sudden deafness, also known as sudden deafness. It is a sudden onset of sensorineural deafness of unknown origin. It can progress from mild hearing loss to severe deafness within minutes, hours or 1-2 days. The main manifestations of patient visits are: 1. Deafness: It often occurs when you wake up in the morning with sudden deafness, or when you feel significant hearing loss only when you use the telephone or talk at a certain time, half of the people first feel a sense of stuffiness in the ear, or obstruction, and some have sudden hearing loss after tinnitus, often with unilateral onset. Generally, it is not easy to recover from heavy hearing loss, and the recovery is even worse for those with vertigo. 2. Tinnitus: About 70% or more are accompanied by tinnitus, which can occur simultaneously with deafness or sequentially with deafness. Buzzing tinnitus, monotonous tinnitus of different heights, unilateral tinnitus, high pitch, heavy, more stubborn, and its recovery is often not synchronized with hearing recovery. Because it is difficult for patients to accept tinnitus, it is sometimes the main reason for patients to visit the clinic. 3. Vertigo: About 47% of patients experience mild or temporary vertigo that lasts from a few days to a few weeks. In addition, a few patients may experience nausea or vomiting. More than 72% of patients with sudden deafness who start treatment within 1 week of onset can be cured or have partial recovery of hearing; 50% of those who start treatment in 8-12 days; 20% of those who start treatment in 20-30 days; and it is difficult to recover in more than 2 months. For this reason, the earlier the treatment, the better the prognosis. Once the cause of unexplained hearing loss occurs, you should go to the hospital as soon as possible.