A bubble in the mouth does not go away, usually with oral ulcers, trauma, oral herpes and other factors related to the general can be treated with metronidazole, cotrimoxazole mouthwash, acyclovir and other drugs. 1. Mouth ulcers: mouth ulcers are usually caused by dry weather body immunity reduction leading to infection, usually manifested as swollen gums, dry mouth and other symptoms, you can use metronidazole, levofloxacin and other anti-infective drugs under the guidance of the doctor. 2. Trauma: oral trauma is usually inattentive to the bite, usually manifested as oral mucosal ulcers, bleeding and other symptoms, can be used under the guidance of the doctor compound chlorhexidine mouthwash, ceftazidime and other drugs. 3. Oral herpes: oral herpes is generally caused by viruses entering the oral cavity caused by the damage to the oral mucosa, usually manifested as oral pain, itching and other symptoms, usually under the guidance of the doctor through the acyclovir, ribavirin and other drugs treatment. If you are not feeling well, you should go to the hospital in time, under the guidance of a physician, to give targeted treatment after a clear cause, not blindly use their own medication.