(1) local symptoms: children with adenoid hypertrophy block the posterior nostril and pharynx of eustachian tube, which may cause otorhinolaryngology and other symptoms, such as open mouth breathing during sleep, falling back of tongue root, frequent snoring, restless sleep at night, excessive nasal secretions, nasal obstruction when speaking, vague voice, facial bone development disorder caused by long-term open mouth breathing, long maxilla, high arch of hard palate, irregular dentition, and so on. There is dyskinesia between swallowing and breathing, which often leads to choking, and the downward flow of secretions stimulates the respiratory mucosa, which is prone to bronchitis. Due to the obstruction of eustachian tube, it is easy to cause suction loss due to non-suppurative otitis media and tympanic membrane invagination.

(2) Systemic symptoms: Systemic nutritional and developmental disorders often occur, mainly manifested as symptoms of chronic toxic reflex nervous system, such as dull expression, chest tightness, pulmonary atelectasis, long-term chicken chest or flat chest, and a few cases of pulmonary heart disease or even acute heart failure due to chronic nasal congestion and long-term hypoxia.