Sleep blowing, indicating transoral exhalation, may be caused by muscle relaxation, nasal polyps, colds and rhinitis, obesity and other factors. 1. Muscle relaxin: after sleeping, snoring as well as sleep blowing will occur due to the looseness of pharyngeal muscles and incorrect sleeping posture and poor breathing, without other clinical manifestations, no special treatment is needed. 2. Nasal polyps, colds and rhinitis: nasal lesions lead to edema of the nasal mucosa, the nasal passages are not well ventilated, and the gas is exhaled from the mouth, which will lead to the phenomenon of blowing in sleep. 3. Obesity: it may be related to excessive diet, neck fat accumulation and endocrine factors, which will lead to open-mouth breathing when the pressure of the upper airway increases during sleep, and may be accompanied by snoring, sleep disorders and other manifestations. Sleep blowing patients, it is recommended to actively seek medical examination to clarify the diagnosis, to avoid adverse effects.