Otitis media is mainly due to pathogen infection, Eustachian tube obstruction and other conditions, and is also associated with foreign bodies in the ear canal, seasonal changes and other factors. 1. Basic etiology: (1) Pathogen infection: generally acute suppurative otitis media may be due to infection by pathogenic bacteria such as hemolytic streptococcus, staphylococcus, pneumococcus and so on. In the case of chronic suppurative otitis media, it is considered to be related to infections such as Staphylococcus aureus and Escherichia coli. In case of chronic secretory otitis media, it is mostly considered to be caused by infections such as influenza virus and adenovirus. (2) Eustachian tube obstruction: usually hypertrophic rhinitis, chronic sinusitis, adenoid hypertrophy, nasopharyngeal tumors, etc., can lead to Eustachian tube obstruction, so that the normal secretions of the middle ear can not be discharged, and ultimately induced by infection. 2. Triggering factors: if the patient usually poor living habits, smoking and other bad habits, will make the sinuses, pharynx and other stimulation, which will increase the risk of otitis media. The presence of foreign bodies in the ear canal, seasonal changes caused by upper respiratory tract infections, decreased immunity and other factors can also induce otitis media. It is recommended that patients with otitis media identify the cause of the disease in a timely manner and take reasonable treatment measures under the guidance of a doctor to avoid delaying their condition.