Patient, male, 33 years old, main cause: sudden hearing loss in the right ear for 2 days. The patient had a sudden hearing loss in the right ear 2 days ago and went to an outside hospital for an audiogram: hearing loss of 90 dB in the right ear at 1k and 2k Hz. Hyperbaric oxygen therapy was started 2 days after the onset of the disease and the hearing basically returned to normal after 14 sessions. (The figure below shows the audiogram before hyperbaric oxygen, after 8 hyperbaric oxygen sessions and after 14 hyperbaric oxygen sessions, respectively. The guidelines also point out that, in contrast to hormone therapy, hormone therapy is not recommended. The guidelines also state that hyperbaric oxygen therapy has fewer side effects and is more acceptable to patients than hormones. The guidelines make several recommendations for hyperbaric oxygen therapy: 1. Age is an important determinant of the effectiveness of hyperbaric oxygen therapy, with younger patients having better outcomes than older patients (the age limit is 50-60 years); 2. Early treatment is more effective than late treatment; (2 weeks to 3 months is considered early); 3. (moderate to severe is defined as hearing loss of more than 60 dB). Although a clear cause of sudden deafness has not been found, many clinical patients have some obvious history of exertion, emotional stress, mental tension and cold, so the incidence of sudden deafness has been increasing year by year in recent years. Since our department was established 20 years ago, we have treated nearly 10,000 patients with sudden deafness. Now, based on our accumulated experience, we would like to summarize the opinions of hyperbaric oxygen therapy for sudden deafness as follows: 1. Hyperbaric oxygen should be started as soon as possible, the course of treatment should be sufficient, and we should not give up lightly. 1 of our most frequent patients with sudden deafness has recovered hearing significantly after nearly 80 times of treatment; 2. It is normal for hearing to recur during the treatment. Generally, hearing is recovered before tinnitus, so there is a possibility that tinnitus may be aggravated; 4. During the treatment process, there may be air pressure injury that may cause ear discomfort, but it is usually possible to recover completely after rest.