Adenoids, also known as pharyngeal tonsils, are lymphatic tissues located in the nasopharynx. Infection of the upper respiratory tract can cause inflammation of the adenoids, and recurrent acute inflammation or chronic inflammation that does not heal can lead to hyperplasia of the adenoids. Acute inflammation of the adenoids can cause fever and headache, and the spread of inflammation to the front can cause sinusitis and to the bottom can cause tracheitis, bronchitis and even pneumonia. In severe cases of hypertrophy, children can only breathe with their mouths open, snoring and even breath-holding can occur during nighttime sleep, and children can be restless, agitated or even wake up from sleep, and some can wet the bed. Breath-holding, lack of oxygen and sleep disturbance at night can affect the physical and intellectual development of the child, resulting in delayed growth, decreased academic performance and hyperactivity. Long-term open-mouth breathing can also affect the development of the jaw and face, resulting in irregular teeth, high arched hard palate, deviated nasal septum, narrow face and other so-called “adenoid face”. The treatment of adenoid hypertrophy and chronic inflammation is mainly surgical, and the new endoscopic surgical method is safe and effective.