Swollen gums in general can use metronidazole injection for mouth rinsing, incision and drainage of pus surgery, according to the specific disease periodontal treatment or root canal treatment. 1. Metronidazole injection gargle: most of the anaerobic bacteria have a strong antibacterial effect, used for gargling, oral drug distribution, absorption effect is good, the efficacy is remarkable; may appear nausea, vomiting adverse reactions, but the probability of occurrence is low; have a history of allergy to metronidazole or blood disease patients are prohibited to comply with the doctor’s instructions for use of the drug. 2. Incision and drainage: the swollen part of the gums will be incised to drain the pus, and the patient needs to change the medicine for several times until the swelling disappears; although it is relatively simple, but it is easy to cause pain, and the filling of the gauze makes the drainage not smooth. 3. Periodontal treatment: If the swelling is caused by periodontitis, systematic periodontal treatment is needed, including scaling, scraping and root planing, etc., so as to remove the periodontal irritants. 4. Root canal therapy: Gums that are swollen due to apical periodontitis require root canal therapy for complete cure. If the swelling of the gums fails to subside, it is recommended that the patient go to the local dental hospital to prevent further deterioration of the disease, and the use of medication should be in accordance with the doctor’s instructions.