Also called periodontitis, gum disease is a severe gum infection that damages the soft tissues that surround a tooth. If left untreated, periodontitis can destroy the bone that supports the teeth. Teeth can become loose, and eventually need to be removed. Symptoms of gum disease include gums that are swollen or puffy, tender to the touch or bleed easily, or pus develops between the teeth. Periodontitis can be prevented with regular checkups, and at-home care that includes daily bruising, rinsing with a mouthwash, and frequent flossing.