How much sleep do humans need?

Our sleep requirements change throughout our lifetime.

For example, babies sleep much more than older children, women need more rest during pregnancy, and we all need more sleep during illness so our bodies can recover.

Also, some individuals just plain seem to need more sleep than others.

Here are some general guidelines for how much sleep we need in a 24-hour period at different life stages:

• Birth to 2 months: 10 to 20 hours
• 2 months to 18 months: 13 to 15 hours
• 18 months to 5 years: 11 to 14 hours
• 5 years to 12 years: 9 to 11 hours
• Teenagers: 8 to 10 hours
• Adults: 7 to 9 hours

How do you know when you're getting the right amount of sleep for you? When you wake up naturally, with no alarm clock or other disturbance rousing you from slumber.