Staying up late once in a while might not have much of an effect on your next day at work. You might drink an extra cup of coffee, but you’ll still be productive. However, continually not getting enough sleep can have a serious impact on how well you perform everyday tasks. Unfortunately, just under half of all Americans say that poor sleep affects their daily tasks at least once a week.

“Our lack of sleep is an epidemic and it’s causing some major negative effects because it impairs judgment,” said Michael C. Marino, D.O., medical director of Geisinger Sleep Labs.

Until the 1950s, sleep was thought to be a time when our brains were essentially inactive. But research throughout the last century has showed that our brains are very active during sleep. When we sleep, our brain repairs itself—proteins, which are a foundation for cell growth, increase in production during deep sleep.

During sleep, researchers also believe the brain clears itself of other toxic proteins that build up while we’re awake. If we don’t sleep, this buildup of waste can contribute to impaired judgment.

What happens when we don’t sleep

When you don’t get enough sleep, you might feel drowsy during the day, have a hard time focusing at work or find yourself dozing off on the train or bus. Not getting enough sleep has a number of effects, including:

  • Slowed reaction times
  • Reduced performance and alertness
  • Memory problems
  • A weakened immune system

“Reducing your typical amount of sleep by even 30 minutes in one night can reduce your alertness and begin impacting your daily tasks,” said Dr. Marino. This could mean that your work could suffer and, worse, you could even injure yourself or someone else. Driving drowsy accounts for an estimated 100,000 car crashes each year, according to the National Highway Traffic Safety Administration.

How much sleep do we need?

The amount of sleep each person needs varies throughout his or her life; it also varies from person to person. But the general guidelines are as follows:

  • Infants: 12-15 hours
  • Toddlers: 11-14 hours
  • Pre-school children: 10-13 hours
  • School-age children: 9-11 hours
  • Teenagers: 8.5-9.5 hours
  • Adults: 7-9 hours

Unfortunately, if you’re not following these guidelines and getting seven to nine hours as an adult, your body won’t simply adapt to this change. 

“If you are consistently sleep deprived, the amount of sleep you need to feel rested again will increase. Your body doesn’t adapt to sleep loss,” said Dr. Marino.

Tips for a better night’s sleep

If you find that you feel drowsy during the day and you’re not as productive as you could be, it’s important to try to get more rest.

Set a schedule: Try going to bed and waking up at the same time every day—even on weekends. This will put your brain and body on a healthy schedule throughout the week.

Avoid caffeine: Your sleep troubles may be a result of too much caffeine. Try limiting your coffee or tea intake, and don’t forget to consider other foods that contain caffeine.

Refrain from drinking: Having a drink or two before bed might relax you, but the sleep you get after drinking isn’t high quality. “Sleep after drinking tends to be lighter and less restorative than completely sober sleep,” said Dr. Marino.

Turn screens off: The blue light emitted by your TV, tablet or smartphone could keep you awake at night. Turn these devices off at least an hour before bed to get a good night’s sleep.

Relax: Get into the habit of a relaxing routine before bed to calm yourself. Reading, taking a bath or meditating can help you get in the right frame of mind before sleep.

Exercise: Daily exercise can help you sleep (and prevent a number of other health issues). Try walking, running or working out for 20 to 30 minutes a day, but end your workout at least three hours before bedtime. Otherwise, you might feel too energized to relax.

“If you have tried sleeping tips and still don’t feel rested, talk to your doctor about sleep-related disorders,” said Dr. Marino.