Gum bulge is usually caused by periodontal abscess or periapical abscess, which can not be cured by itself, and requires periodontal treatment or root canal treatment after thorough drainage of pus, as follows. 1. Periodontal abscess: Periodontitis develops into advanced stage and periodontal abscess will appear, and a bulge appears on the surface of the gums. The pus can be drained from the periodontal pocket or gingival surface, and after the pus is drained, supragingival cleaning and subgingival scraping are performed to thoroughly clean the plaque and tartar and other irritants, and eliminate periodontal inflammation. 2. Periapical abscess: purulent periapical abscess progresses to the stage of submucosal abscess, which will appear as a bulge in the gingiva. Gingival incision and placement of drainage strips can drain the pus. Root canal treatment can be performed at the same time or later to eliminate periapical and root canal system inflammation. There may be other causes of bulging gums and it is advisable to visit the hospital promptly.