Sleeping with a grunting sound may be caused by nasal stenosis, pharyngeal stenosis and sleep apnea. 1. Nasal stenosis: Chronic rhinitis, deviated septum, sinusitis, and nasal swelling can lead to nasal stenosis and poor nasal ventilation. When air passes through the narrowed portion of the nasal passages, a humming sound occurs. 2. Pharyngeal stenosis: symptoms such as enlarged tonsils, enlarged uvula, collapsed soft palate, falling back of the tongue, and hypertrophy of the tongue can lead to pharyngeal stenosis during sleep, and when air passes through the narrowed part of the throat, vortexes are formed, and a humming sound will be made. 3. Sleep apnea: When patients have prolonged exhalation during sleep, they will make a humming sound, which belongs to sleep apnea. When the patient makes a grunting sound while sleeping, it is recommended that the patient go to the hospital for examination and diagnosis, and under the guidance of the doctor for treatment.