The main side effects of hyperbaric chambers include oxygen toxicity and gas pressure injuries. Patients are advised to report any discomfort after using hyperbaric oxygen chambers to their healthcare provider immediately to avoid accidents. Hyperbaric oxygen chambers are a common medical device that is mainly used for people suffering from carbon monoxide poisoning, partial ischemic-hypoxic encephalopathy, and gas embolism. Although hyperbaric oxygen chamber can correct the hypoxic state of the patient’s body, effectively relieve respiratory distress, consciousness disorder and other conditions, but also has many side effects, such as oxygen poisoning, air pressure injury. 1. Oxygen toxicity: Excessive oxygen tends to stimulate the body and inhibit respiration, thus prolonged use of hyperbaric oxygen chambers may lead to oxygen toxicity. Patients will have central nervous function damage, optic nerve damage and other manifestations. It is recommended to follow the medical advice to immediately reduce the oxygen concentration, while utilizing diazepam, phenobarbital, etc. for sedation. 2. Air pressure injury: in addition to oxygen toxicity, patients may also be accompanied by middle ear air pressure injury, which is mainly manifested as dizziness, headache, tinnitus, and even tympanic membrane perforation. When the symptoms are mild, patients are advised to pay more attention to rest and reduce physical activities. When symptoms are severe or persist for a long period of time, patients are advised to seek immediate medical attention for tympanotomy or tympanocentesis to relieve discomfort. Patients utilizing hyperbaric oxygen chamber treatment are advised to monitor their condition during and after treatment. When there is discomfort, feedback to the healthcare provider is timely.