The amount of sleep you need each day will change over the course of your life. Although sleep needs vary from person to person, the chart below shows general recommendations for different age groups.
|Age||Recommended Amount of Sleep|
|Newborns||16–18 hours a day|
|Preschool-aged children||11–12 hours a day|
|School-aged children||At least 10 hours a day|
|Teens||9–10 hours a day|
|Adults (including the elderly)||7–8 hours a day|
If you routinely lose sleep or choose to sleep less than needed, the sleep loss adds up. The total sleep lost is called your sleep debt. For example, if you lose 2 hours of sleep each night, you'll have a sleep debt of 14 hours after a week.
Some people nap as a way to deal with sleepiness. Naps may provide a short-term boost in alertness and performance. However, napping doesn't provide all of the other benefits of night-time sleep. Thus, you can't really make up for lost sleep.
Some people sleep more on their days off than on work days. They also may go to bed later and get up later on days off.
Sleeping more on days off might be a sign that you aren't getting enough sleep. Although extra sleep on days off might help you feel better, it can upset your body's sleep–wake rhythm.
Bad sleep habits and long-term sleep loss will affect your health. If you're worried about whether you're getting enough sleep, try using a sleep diary for a couple of weeks.
Write down how much you sleep each night, how alert and rested you feel in the morning, and how sleepy you feel during the day. Show the results to your doctor and talk about how you can improve your sleep. You can find a sample sleep diary in the National Heart, Lung, and Blood Institute's "Your Guide to Healthy Sleep."
Sleeping when your body is ready to sleep also is very important. Sleep deficiency can affect people even when they sleep the total number of hours recommended for their age group.
For example, people whose sleep is out of sync with their body clocks (such as shift workers) or routinely interrupted (such as caregivers or emergency responders) might need to pay special attention to their sleep needs.
If your job or daily routine limits your ability to get enough sleep or sleep at the right times, talk with your doctor. You also should talk with your doctor if you sleep more than 8 hours a night, but don't feel well rested. You may have a sleep disorder or other health problem.