The causes of sleep especially, consider the following aspects: 1, the physiological situation, if the patient is in a long-term sleep deprivation, brain fatigue, has not been able to rest, relaxation, will lead to patients in a certain period of time to show more sleep. 2, the patient sleep especially with the blood is in a high fat, high viscosity state has a relationship, will lead to the patient’s brain in chronic ischemia, lack of oxygen stage, so sleep especially. 3, if the elderly usually social activities are less, will lead to always fall asleep during the day. 4, patients sleep more to consider is episodic sleeping disease, is the cause of the disease, although not very clear, but patients often show daytime sleepiness. Narcolepsy refers to patients who have irresistible episodes of sleepiness during the day, mostly in non-sleep environment, non-sleep time performance to fall asleep.