Sleeping with mouth open snoring may be caused by obesity, may also be caused by nasal septum deviation, pharyngeal tonsil hypertrophy and other diseases. 1. obesity: for obese people, due to their own airway nose often narrow, night sleep nerve excitability is reduced, resulting in muscle relaxation, making the upper pharyngeal airway collapsed, and then when the airflow through the mouth will appear open snoring. 2. Deviated nasal septum: the main cause of this disease is the uneven development of the cartilage of the nasal septum, which makes the connection between the bone and the bone abnormal, and it may also be related to heredity, traumatic injury, nasal tumor, nasal polyps and other reasons. As the deviated septum will lead to the obstruction of nasal cavity, so the patient will continue to open mouth breathing, snoring and other phenomena, the patient will also have a headache, nose bleeding and other symptoms. 3. Enlarged pharyngeal tonsils: the causes of this disease include adjacent or local inflammation, nasal purulent secretion stimulation, perverse reaction, improper diet and so on. Because pharyngeal tonsil hypertrophy affects normal breathing, there will be symptoms such as sleeping with open mouth breathing, snoring, etc. There will also be bad breath, dry mouth, nasal congestion, stuffy ears and other symptoms. There are more reasons that lead to snoring while sleeping with mouth open, and you should go to the hospital to clarify the specific cause of the disease.