When the atmospheric pressure changes suddenly, the Eustachian tube opening cannot open smoothly to regulate the pressure in the tympanic cavity, thus causing tympanic cavity damage, similar to aseptic otitis media, which is called barotrauma. Under normal circumstances, the Eustachian tube opens instantly when swallowing, yawning, and blowing the nose, so that the air pressure in the tympanic cavity and the external air pressure remain balanced. When the Eustachian tube has pathological changes, such as colds, sinusitis, nasopharyngeal tumors, nasal polyps, nasal septum deviation, palatopharyngeal muscle paralysis, and maxillary joint malocclusion, or during sleep and coma, the Eustachian tube loses its normal function of regulating air pressure, which is an internal factor. When the external air pressure changes suddenly, such as naval diving, air force takeoff, and hyperbaric oxygen chamber treatment, if there are no good protective measures, it is easy to cause barotrauma, which is an external factor.