Redness, swelling and pain in the root of the tooth are usually caused by apical periodontitis, and the treatment is based on root canal treatment, with the use of analgesics to relieve pain, the use of antibacterial drugs to reduce the inflammation, if an abscess is formed, it is necessary to incise and drain pus to deal with it, and if a cyst is formed, it is necessary to have apical surgery. Root canal treatment is currently the most effective and commonly used method of treating periapical inflammation, with medication to achieve good therapeutic effect. Commonly used drugs include analgesics, such as ibuprofen, diclofenac sodium, etc., as well as antibacterial drugs, such as metronidazole, amoxicillin and so on. Medications should be used under a doctor’s supervision. Periapical inflammation may produce pus and form abscess, which should be incised and drained, along with root canal treatment and medication; if a cyst is formed, apical surgery should be performed after root canal treatment. It is recommended to go to the hospital in time for early and regular treatment.