How many hours is considered enough sleep?
Sleep needs vary from person to person--and vary across a person's lifetime, says Michael Timothy Smith, MA, PhD, director of the Behavioral Sleep Medicine Program at Johns Hopkins University, in this HealthMakers video.
Up Next
What is considered a good night's sleep?
Can you catch up on sleep?
Why is sleep so important for the mind and body?
How does sleep affect chronic pain?
What are good bedtime rituals to prepare for sleep?
Why do so many people have trouble sleeping?
Does alcohol interfere with sleep?
How important is light for sleep-wake cycles?
What happens to memory during sleep?
3 tips to help train your brain for better sleep
