Suddenly waking up with a hum when fast asleep usually has the following reasons: 1, belongs to neuromodulation dysfunction, usually in patients who have too much light sleep phase and not enough deep sleep phase during sleep, the above clinical symptoms will appear, which is a common clinical symptom and performance of poor sleep quality due to plant nerve dysfunction. 2, suddenly appearing with a hum when fast asleep, usually has brain cells Ischemia and itchiness. When the brain cells are deprived of oxygen and blood supply, a sudden humming sound will appear during sleep, followed by sleep restlessness and sleep disturbance, which is caused by low oxygen content in arterial blood, low partial pressure of oxygen and high partial pressure of carbon dioxide. 3, often related to insufficient blood supply to the cerebral vessels, the above clinical symptoms are caused by incomplete blood supply to the brain cells due to compression of the vertebrobasilar artery during sleep.