1, too much stimulation before bedtime awake, including: ① night before sleep exercise ② strong brain activity at midnight ③ drink a lot of coffee p tea or smoking before bed, ④ bedroom is either too bright light or too much noise, the room temperature is either too cold or too hot. 2, behavior disrupts the sleep rhythm, including: ① sleep irregularly every day ② sleep too much time in bed ③ nap too much during the day, etc.