Sleeping with open mouth snoring is seen in upper respiratory tract stenosis, nasal stenosis, obesity, tongue hypertrophy, tonsil hypertrophy and other conditions. 1. Nasal stenosis: such as nasal septum deviation, turbinate hypertrophy, nasal polyps and other diseases can cause nasal stenosis, resulting in airflow blockage, causing open-mouth snoring. 2. Obesity: Obesity is one of the most common factors that cause snoring. The airway of obese people is narrower than that of normal people. During the daytime, the contraction of throat muscles can keep the airway open. However, at night when sleeping, due to the decline in nerve excitability, resulting in muscle relaxation, the upper airway collapse, the narrow part of the airflow can produce vortex, causing vibration, resulting in open-mouth snoring. 3. Others: enlarged tonsils, enlarged adenoids, enlarged tongue, prolonged uvula, laxity of the pharynx, tongue falling back and so on, all of which can lead to narrowing of the upper airway and cause this symptom. It is recommended that patients consult a doctor in time to check the cause and condition, and actively treat the cause and symptoms to avoid aggravation of the condition.