Correction of mouth breathing requires treatment depending on the cause. If it is caused by poor sleeping posture, the sleeping posture can be changed; if it is caused by nasal disease or oropharyngeal disease, medication or surgical treatment is needed. 1. Bad sleeping posture: For patients who breathe through their mouths due to bad sleeping posture, they should sleep in a side-lying position and avoid excessive head tilting, which can partly improve the situation of breathing through the mouth. 2. Nasal diseases: allergic rhinitis, sinusitis and other causes of turbinate hypertrophy or nasopharyngeal adenoid hyperplasia, affecting nasal ventilation, can cause breathing through the mouth. At this time, conservative treatment can be given to improve nasal ventilation, such as mometasone furoate nasal spray, cetirizine hydrochloride tablets and so on. If the conservative treatment is not effective, we can consider the nasal turbinate and sinus surgery or adenoidectomy. 3. Oropharyngeal diseases: such as enlarged tonsils, teeth or jaw development problems, resulting in breathing through the mouth. In this case, tonsillectomy or orthodontic treatment can be performed to improve mouth breathing. When breathing through the mouth is found, it is recommended to consult a hospital as soon as possible to find out the cause of the disease, and according to the specific cause of the disease to be appropriate drug treatment and corrective measures.