The occurrence of otitis media may be caused by pathogenic infection, Eustachian tube dysfunction and decreased resistance. 1. Pathogen infection: it is divided into bacterial infection and viral infection. Bacterial infections include hemolytic streptococcus, staphylococcus, pneumococcus, and Haemophilus influenzae. Viral infections include adenovirus and respiratory syncytial virus. 2. Eustachian tube dysfunction: Eustachian tube dysfunction can lead to ear infections because normal secretions cannot be secreted, including mechanical and functional disorders. Mechanical disorders include hypertrophic rhinitis, lymphoid hyperplasia, and adenoid hypertrophy in children. 3. Decreased resistance: After the patient’s resistance decreases, the stress response to external stimuli can appear as inflammatory symptoms, and it is also easy to become the basis for pathogenic microorganisms to multiply and develop. After the onset of otitis media, it is not recommended to treat yourself, you need to actively go to the hospital after examination to clarify the cause of standardized treatment.