The common causes of unilateral tonsillar enlargement are mainly the following: First, recurrent inflammation of the pharynx or tonsils, stimulating tonsillar enlargement, this condition is accompanied by unilateral heavier pharyngeal pain and sometimes fever, which can recur. Second, tonsillar hyperplasia, manifested as painless enlargement of the tonsils, with a long history, patients can feel no obvious discomfort. If the symptoms are not obvious or the changes are not significant, no treatment is needed, but attention should be paid to regular review; if it affects breathing or significant changes occur within a short period of time, surgical removal is recommended. Benign tonsillar tumor, mostly seen as a swelling on the surface of tonsil, gradually grows up, may not have obvious pain and other discomfort, can be found during body check, this case is recommended to be removed surgically and take specimens for pathological examination. Malignant tumor of tonsil, mostly seen in tonsil swelling rapidly in a short period of time, may have no obvious symptoms or only a foreign body feeling in the pharynx, biopsy pathology test can be a clear diagnosis, need to carry out surgery.