The hazards of children staying up late include affecting growth and development, affecting intellectual development, and lowering immunity. 1. Affect growth and development: growth hormone is mainly secreted at night. Children stay up late will affect the secretion of growth hormone, the secretion will be reduced to affect the child to grow taller. 2. Impact on intellectual development: children are prone to stay up late so that the brain can not get enough rest, affecting the growth and development of the brain, there may be intellectual underdevelopment, inattention, memory loss and so on. 3. Lower immunity: children stay up late may also lead to the body’s immune ability to decline, prone to respiratory, gastrointestinal tract and other parts of the infection. There may be other hazards to children staying up late. Parents should pay attention to help children develop healthy sleeping habits, go to bed early and get up early, try not to stay up late.