Children sleeping with their mouths open is not necessarily adenoid hypertrophy, there are many reasons, adenoid hypertrophy is one of the reasons, it may also be related to the deviated nasal septum, nasal polyps and other diseases. It is recommended to consult a doctor in time to find out the cause of the disease. 1. Adenoid hypertrophy: Children’s adenoid hypertrophy will obviously block the posterior nasal passage, resulting in children’s nasal congestion and inability to inhale, so they can only open their mouths when sleeping. It is recommended to consult a doctor in time, and the primary disease can be actively treated according to the individual situation, and if necessary, surgery is needed. 2. Nasal septum deviation: when the nasal septum is deviated to one side, it will lead to reduced ventilation or blockage of one side of the nasal cavity, which will lead to the situation of children sleeping with their mouths open. 3. Nasal polyps: Nasal polyps mainly cause symptoms of runny nose and nasal congestion, and in severe cases, children may have difficulty in breathing and sleep with their mouths open. Surgery can be performed under the guidance of a doctor. Children sleeping with their mouths open, it is recommended to go to the hospital in time for relevant examinations, under the guidance of the doctor to do targeted treatment.