Most of the adenoidectomy will not cause side effects, but in a few cases, there may be nasopharyngeal scarring, hearing loss, tinnitus, recurrence and so on. 1. Nasopharyngeal scarring: Adenoidectomy may cause nasopharyngeal scarring, which may produce a foreign body sensation, and in severe cases, it may also cause nasopharyngeal adhesions, resulting in symptoms of Eustachian tube adhesions or Eustachian tube patency. 2. Hearing loss and tinnitus: The scar and mucous membrane adhesion after surgery may cause blockage of the Eustachian tube, resulting in secretory otitis media, which may cause hearing loss and tinnitus. 3. Recurrence: If accompanied by chronic sinusitis and other diseases, the recurrence of nasal inflammation may cause adenoid re-growth. Nowadays, the surgical equipment is more complete and the technology is more mature, and the side effects of the surgery have been reduced to a very low level.