1, etiology: 1, mechanical obstruction: such as pediatric adenoid hypertrophy, hypertrophic rhinitis, nasopharyngeal tumors or lymphatic tissue hyperplasia, long-term nasopharyngeal filling, etc.. 2, dysfunction: the division of the pharyngeal tube to open and close the muscle contraction is weak; pharyngeal tube cartilage elasticity is poor, when the drum chamber is in a negative pressure state, the wall of the pharyngeal tube cartilage section is prone to collapse, this is one of the anatomical and physiological basis for the high incidence of pediatric secretory otitis media. 3. Infection In the past, it was thought that secretory otitis media was a sterile inflammatory disease. Recent studies have found that about 1/2-1/3 of the middle ear effusions are positive for bacterial cultures, with the main causative organisms being Haemophilus influenzae and Streptococcus pneumoniae. 4. Immune response The immune system of pediatric patients is not fully developed, which may also be one of the reasons for the higher incidence of pediatric secretory otitis media. The main symptoms are as follows: 1. Hearing loss: hearing loss, self-hearing enhancement. When the head is tilted forward or to the healthy side, the hearing can be temporarily improved because the accumulated fluid leaves the cochlea transmission (dislocation hearing improvement). When the fluid is viscous, the hearing may not change due to the change of head position. Children are often brought to the doctor by their parents because they are slow to respond to sound, inattentive, and have decreased academic performance. If one ear is diseased and the other ear has normal hearing, it may go undetected for a long time and be discovered during a physical examination. 2. Earache: In acute cases, there may be vague earache, which is often the first symptom of the patient, and it may be persistent or throbbing. In chronic cases, the ear pain is not obvious. The disease is very much related to the feeling of occlusion or stuffiness in the ear, which can be temporarily relieved after pressing the ear screen. 3. Tinnitus: It is mostly low-pitched and intermittent, such as “splintering” sound, buzzing sound and running water sound. When the head moves or when yawning or blowing the nose, the sound of air passing through water can appear in the ear. 4. The skin around the patient has a feeling of “woodiness” and a sense of psychological boredom. Treatment: Removal of middle ear fluid, improvement of middle ear ventilation and drainage, and treatment of the cause of the disease are the principles of treatment for this disease. Disease prevention: Strengthen physical exercise and prevent colds. Conduct health education, raise parents’ and teachers’ awareness of the disease, and conduct regular screening acoustic conductivity tests for children under 10 years of age. Actively treat nasal and pharyngeal diseases.