Although the hyperbaric oxygen chamber is more effective, there are some relative precautions. For the screening of the crowd, to do a preliminary determination, in order to allow access to the following conditions are prohibited to enter the hyperbaric oxygen chamber: 1, body temperature > 38.5 ℃, blood pressure > 160mmHg; 2, tuberculosis, pulmonary herpes patients if the hyperbaric oxygen chamber, may be due to the rupture of the air pressure caused by the pneumothorax; 3, did not get the treatment and control of patients with tumors, if you enter the hyperbaric oxygen chamber, it may promote tumor 4, otitis media, because the Eustachian tube is blocked, into the oxygen chamber will cause the pressure inside and outside the tympanic membrane is not equal, may cause tympanic membrane rupture; 5, small children to do hyperbaric oxygen chamber, you must do fundus examination. Because of the imperfect development of the fundus of infants and young children, if not checked, it may cause damage to hearing and vision, so it must be normal development of the fundus to do.