Adenoid hypertrophy in children is more common in clinical practice and has attracted increasing attention from parents and physicians. The adenoids are a mass of lymphatic tissue located in the posterior wall of the nasopharynx (near the posterior nostril) and are generally largest at the age of 6 or 7 and gradually degenerate and shrink at the age of 10 or so. As children have low immunity and are prone to upper respiratory tract infections, one or a few colds can cause the adenoids to grow and enlarge, and then the cold gets better but the adenoids do not shrink. Adenoid hypertrophy can cause many problems. Adenoid hypertrophy or concomitant tonsillar hypertrophy in children can cause obstructive sleep apnea hypoventilation syndrome. The symptoms of this disorder are sleep snoring with breath-holding (i.e., apnea) and open-mouth breathing. The prevalence of obstructive sleep apnea syndrome in children is about 2%, mainly occurring at the age of 2-6 years. Apnea and hypoxia can affect the growth and development of children to varying degrees, such as causing abnormalities in respiration, development, neurocognition, and in severe cases, even causing sudden death in children. Long-term breathing through the mouth, under the impact of airflow, the hard palate is high arched, which will make the facial development deformed, appearing short and thick upper lip cocking, lower jaw sagging, nasolabial groove disappeared, upper incisors protruding, poor bite, etc. Due to the restricted movement of facial muscles, the child’s face lacks expression, which is called “adenoid face” in medical science. The enlarged adenoids and tonsils can obstruct upper airway breathing, making children prone to recurrent upper respiratory tract infections, rhinitis and sinusitis, resulting in further enlargement of tonsils and adenoids, forming a vicious circle that is not easily relieved. Adenoid hypertrophy in children can cause nasal and sinus inflammation that is not easily drained, compression or obstruction of the eustachian tube (the passage between the middle ear cavity and the nasal cavity), inflammation of the adenoids themselves, and poor cartilage elasticity of the eustachian tube in children, all of which can cause exudative otitis media. According to our clinical statistics, the incidence of exudative otitis media among children hospitalized with obstructive sleep apnea hypoventilation syndrome is 74.3%. Therefore, children with obstructive sleep apnea hypoventilation syndrome should be more alert to oozing otitis media. Adenoid hypertrophy in children can be treated very well with endoscopic, minimally invasive surgery for removal.