Adenoid hypertrophy is not the only cause of open mouth sleep, cause open mouth sleep is relatively more reasons, specifically such as adenoid hypertrophy, rhinitis, nasal structure changes, nasal polyps, tonsil hypertrophy and so on. 1. Adenoid hypertrophy: children with physiological adenoids, hypertrophy tends to block the posterior nostrils, resulting in nasal congestion, can not breathe, can only open the mouth when sleeping. 2. Rhinitis: especially chronic rhinitis, the nose will be blocked for a long time, the nose breathing is affected during sleep, can only sleep with the mouth open. 3. Nasal structure changes: nasal septum deviation will cause nasal congestion and other conditions, the patient will also have the symptom of sleeping with the mouth open. 4. Nasal polyps: Nasal polyps tend to block the nasal cavity, which can cause the symptom of open-mouth breathing. 5. Enlarged tonsils: enlarged tonsils can easily lead to narrowing of the pharyngeal cavity, which will block the nasopharyngeal area when lying down or prone, resulting in breathing difficulties. When you sleep with your mouth open, it is recommended that you go to the hospital in time for relevant examinations and treatments.