The inability to sleep with the mouth closed may be caused by long-term open-mouth breathing, or may be caused by adenoid hypertrophy, temporomandibular joint disorder syndrome and other diseases, the patient needs to take general measures, medication, surgical treatment and other ways to address the cause of the disease. 1. Long-term open-mouth breathing: If you habitually breathe with your mouth open, you may develop a condition where you cannot close your mouth during sleep. If such a situation occurs and no other discomfort occurs, it is a normal phenomenon. The habit of breathing through the mouth can be corrected on a daily basis. 2. Adenoid hypertrophy: patients with adenoid hypertrophy, due to long-term airway obstruction, nasal congestion can occur, the patient will unconsciously appear mouth breathing. In this kind of situation, patients can choose surgical treatment according to their own situation, such as adenoidectomy, plasma radiofrequency ablation, and so on. 3. Temporomandibular Joint Disorder Syndrome (TMJDS): The inability to close the mouth during sleep may also be caused by TMJDS. If the patient has uncomfortable symptoms, oral non-steroidal anti-inflammatory drugs, such as ibuprofen, acetaminophen and so on. Or, joint cavity irrigation, arthroscopic surgery, and open surgery may be taken. There are many reasons that cause patients to have mouth that can not be closed in sleep, it is recommended that patients go to regular hospitals, identify the cause of the disease, and take treatment measures. Medications should be taken under the direction of a physician.