The science of sleep: How many hours do you need?

Updated by Jenilee Matz, MPH
The science of sleep: How many hours do you need?

Conventional wisdom says eight hours is key when it comes to sleep.

But recent studies show eight might not be the magic number for everyone. So how do you know you're getting the sleep you need?

Why is sleep so important?

Most of us agree that we don't get enough of it. But that dragging, heavy-lidded feeling isn't the only bad result of sleep deprivation - poor sleep over time can lead to serious health risks. Short sleep duration is linked to obesity, type 2 diabetes, heart disease, depression, and substance abuse. Lack of sleep also increases the risk of motor vehicle accidents. (Drivers, take note: the Centers for Disease Control and Prevention (CDC) cites tiredness as a factor in up to 6,000 fatalities each year.)

What can sleep do for me?

Not only do healthy sleeping habits help lower the risk for sleep-related accidents and certain health conditions, but good sleep can also help you:

  • Lower stress levels and improve mood
  • Maintain a healthy weight
  • Avoid getting sick
  • Think more clearly and perform better on the job
  • Make safe choices and reduce the chance of injuries

How many hours are enough?

Sleep needs are individual and vary based on age. Adults generally find seven to nine hours per night adequate, while active, school-age children can require as many as 11 hours. The quality of sleep, or how well you sleep, also affects the quantity you need. People with frequently interrupted sleep, such as those with a sleep disorder like sleep apnea, won't feel as rested as people who sleep soundly through the night. And research has also linked sleeping too much to higher risk of diabetes, heart disease, headaches, back pain and obesity.

So the question is how do you find the right number of hours of sleep per night for you?

Get on track for better sleep.

It can take trial and error to find out how much sleep you need. Consider keeping a sleep log and noting your mood, energy level and health after different amounts of sleep. If you're feeling productive and happy on eight hours of sleep, you've likely found you're sweet spot. On the other hand, if you find it difficult to wake up or you rely on caffeine throughout the day to stay awake, there's a good chance you need more sleep.

Technology can also help you track your sleep patterns: for example, fitness devices are widely available that offer a peek into how much sleep you get each night. Walgreens' own Balance Rewards for healthy choices platform lets you compare sleep to other vital health metrics, like fitness and weight, to show you how a regular sleep pattern supports your wellness goals - like healthy weight loss. You can even sync your fitness tracker for automatic entry.

Tips for a good night's sleep.

The key to a good night's rest? Consistency - and a plan. The National Sleep Foundation outlines a strategy that includes setting a sleep and wake schedule and a regular bedtime routine, and sticking to it even on weekends. These healthy sleep tips can also help:

  • Practice a bedtime ritual that's relaxing, such as reading a book.
  • Make sure your bedroom is at a comfortable temperature, and minimize sounds and lights.
  • Exercise regularly, but avoid intense workouts late in the evening because it can make falling asleep more difficult.
  • Turn off all electronic devices before bed.
  • Invest in a comfortable pillow and mattress.
  • Avoid alcohol and caffeine close to bedtime.

Worried about your sleep?

Sometimes health problems can keep you from getting adequate sleep. See your health care provider if you have trouble staying awake during the day, or you experience snoring, leg cramps or tingling during sleep, difficulty breathing or gasping during sleep, insomnia (trouble falling or staying asleep) or another issue that keeps you from sleeping well. They can help figure out the cause of your sleep troubles and get you on your way to a better night's sleep.

Clinically Reviewed and Updated on 4/24/2019 by Jenilee Matz, MPH

Sources:

"How much sleep do we really need?" National Sleep Foundation. Web. 9 April 2019.https://www.sleepfoundation.org/excessive-sleepiness/support/how-much-sleep-do-we-really-need

"Drowsy driving: asleep at the wheel," Centers for Disease Control and Prevention. Web. 9 April 2019.https://www.cdc.gov/features/dsDrowsyDriving/index.html

"Are you getting enough sleep?" Centers for Disease Control and Prevention. Web. 9 April 2019.https://www.cdc.gov/features/sleep/

"Sleep drive and your body clock," National Sleep Foundation. Web. 9 April 2019.https://www.sleepfoundation.org/articles/sleep-drive-and-your-body-clock

"How getting enough sleep can help you ward off diseases," National Sleep Foundation. Web. 9 April 2019.https://www.sleep.org/articles/getting-enough-sleep-can-help-ward-off-diseases/

"The concerning link between inadequate sleep and adolescent substance use," National Institute on Drug Abuse. Web. 9 April 2019.https://www.drugabuse.gov/about-nida/noras-blog/2017/07/concerning-link-between-inadequate-sleep-adolescent-substance-use

"Get enough sleep," U.S. Department of Health and Human Services. Web. 9 April 2019.https://healthfinder.gov/healthtopics/category/everyday-healthy-living/mental-health-and-relationship/get-enough-sleep#the-basics_2

"How is sleep quantity different from sleep quality? National Sleep Foundation. Web. 9 April 2019.https://www.sleep.org/articles/sleep-quantity-different-sleep-quality/

"Tweak your workout time to maximize those zzz's," National Institute on Drug Abuse. Web. 9 April 2019.https://www.sleep.org/articles/exercise-time-of-day/

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