Sleep

"Our brains need sleep. Brains process and consolidate our memories while we sleep. It helps our kids remember the important things in life. Sleep helps remove toxins from our brain that build up while we are awake. Without sleep, we can’t form new pathways in the brain that help us learn new things.
Our bodies need sleep. This is especially true for babies and younger children. Sleep is necessary for muscle growth and repair. Some growth hormones are secreted and synthesized during sleep. Poor sleep is associated with obesity, high blood pressure, and diabetes. It also helps our immune system and we are more prone to colds when we are sleep deprived.
Sleep isn’t just about quantity. Quality is important, too. Poor sleep quality is associated with poorer school performance as measured by teacher ratings, grades, and neurocognitive functioning. It can make kids and adults be more moody, angry, and anxious." (MGH Clay Center for Young Healthy Minds)

Children and Sleep (Sleep Foundation)

There are wide individual differences in terms of a child’s sleep needs, but the American Academy of Pediatrics recommends the following guidelines:

Under 1 year: 12 to 16 hours a day

1 to 2 years: 11 to 14 hours a day

3 to 5 years: 10 to 13 hours a day

6 to 12 years: 9 to 12 hours a day

13 to 18 years: 8 to 10 hours a day

Recommendations for good sleep hygiene for children (National Institute of Health):

"Napping during the day should be avoided (for children over age 4)
Appropriate dinnertime should be at least 2 hours before bedtime
Screen time (ie, watching television, playing computer or video games) should be discontinued at least an hour before bedtime
Regular bedtime routine including routine sleep and wake-up times should be maintained
Children should sleep in their own beds
Sleep environment should be dark and quiet; room should not be too hot
Caffeine, nicotine, and alcohol should be avoided"