Pharyngeal tonsils are masses of lymphoid tissue embedded in the mucosa of the nasopharynx posterior wall, part of Waldeyer's lymphatic system and the body’s defence mechanism. When increased in size, these tonsils are called adenoids and can occupy various parts of the pharyngeal cavity.
In some people, excessive growth can cause nasopharyngeal blockade, which increases the risk of recurrent infections and various cardio-respiratory complications.
Often adenoidectomy is performed at the same time as tonsillectomy. Tonsils serve as immuno-protective agents but in some people and especially children who have large tonsils, these glands may act with less or no effectiveness at all and cause frequent throat and ear infections or even obstruct breathing.