The side effects of hyperbaric oxygen therapy mainly include pneumatic pressure injury, oxygen toxicity and decompression sickness, among which pneumatic pressure injury is the most common side effect. Barometric injury includes: 1. Middle ear barometric injury: the most common complication of hyperbaric oxygen therapy. If the eustachian tube is not open for various reasons (epiglottis, rhinitis, nasopharyngeal polyps, poor coordination of pressure adjustment, etc.), the external gas cannot enter the tympanic chamber through the eustachian tube, causing the pressure inside the tympanic chamber to be lower than that outside, and the mucous membrane inside the tympanic chamber to become congested, edematous, and exudate, resulting in otopressure injury, the patient will feel significant pain in the ear, which will continue to increase with the pressure. Prevention methods: ①Patients with upper respiratory tract infection, rhinitis and sinusitis should not enter the cabin. ②During the process of pressure boosting and decompression in the cabin, pay attention to the swallowing action. ③If necessary, you can apply Tianchengnuoer nasal drops or ephedrine nasal drops, etc. to reduce the chance of middle ear air pressure injury. 2, sinus air pressure injury: any blockage of the sinus opening, such as tissue hyperplasia, edema, mucus, etc., can cause sinus air pressure injury. The main manifestation is headache. Prevention methods are similar to ear air pressure injury. 3, pulmonary pneumatic pressure injury: very rare, pulmonary pneumatic pressure injury is seen in patients undergoing high pressure or hyperbaric oxygen therapy in the process of decompression inappropriate breath-holding, coughing, vomiting, convulsions (epileptic grand mal seizures, cerebral oxygen poisoning) when the vocal cords closed, resulting in the trachea and lung pressure is greater than the external pressure. Due to the poor pressure-bearing capacity of the lung tissue, when the pressure difference between inside and outside the lung is greater than 80 mmHg, the lung tissue will over-expand, resulting in the tearing of the alveolar wall, blood vessels, and interstitium and the occurrence of pneumothorax, mediastinal emphysema, and subcutaneous emphysema, which is manifested as sudden chest stabbing pain that increases when breathing, persistent cough, breath-holding, cyanosis, shortness of breath, and in severe cases, life-threatening. Prevention methods: ①Patients with chronic lung diseases, such as pulmonary herpes and pneumothorax, should not enter the chamber. ②Patients receiving treatment in the hyperbaric chamber should not hold their breath for a long time during the decompression process. Second, oxygen poisoning: including brain type, lung type, eye type, hemolytic oxygen poisoning, etc., the body in the inhalation of high concentrations of oxygen for a certain period of time may lead to certain organs in the function and structure of the damage. In addition to individuals who are particularly sensitive to oxygen, oxygen toxicity rarely occurs as long as the indications for hyperbaric oxygen therapy are strictly mastered, contraindications are eliminated, and treatment protocols are strictly implemented. Decompression sickness: Because the environmental pressure decreases too much and too fast, resulting in the formation of bubbles in the body tissue and blood, causing obstruction of blood vessels or compression of tissue and causing damage to the body. Hyperbaric oxygen therapy, unless emergency decompression, generally will not occur decompression sickness. IV. Other: Myopia, retinal detachment and cataract may occur occasionally in long-term hyperbaric oxygen therapy. Therefore, the key to prevent the side effects and complications of hyperbaric oxygen therapy is to strictly master the indications of hyperbaric oxygen therapy, eliminate contraindications to enter the cabin, strictly implement the treatment protocol, and instruct the cabin personnel before entering the cabin.