Science Reveals Exactly What Your Smartphone Is Doing to Your Sleep

The news: If you feel like you're not getting a good night's sleep, your cellphone or TV screen might have something to do with it.

According to a newly released study by the National Sleep Foundation, around 89% of adults and 75% of children in America keep at least one electronic device in their bedroom, and a big percentage of them leave their devices on when they go to bed. But while falling asleep with the TV turned on or with music playing might be a common occurrence, it can actually have a big impact on your sleeping patterns.

It all comes down to melatonin, a hormone that tells the body that it's time for bed. But when your body detects light in the room — especially blue light — it can ward off melatonin, making it harder to fall asleep. And as similar research has found, even something as small as a lit-up iPad or smartphone screen is enough to throw you off

"The burst of light from a phone [even if it's just to check the time] can break a sleep cycle," Dr. Jill Creighton, an assistant professor of pediatrics who worked on a similar study at Stony Brook University, said in a statement. "A regular alarm clock is best."

It's unfortunately a very common practice. As shown in the chart below, the majority of American parents and children keep their electronics close at hand:

And there's a noticeable difference between children who kept their electronics on in their bedrooms and those who didn't. For instance, kids who turned off their tablets and phones got almost an entire hour of sleep more than those who kept them on:

The prevalence of electronic devices not only affected the number of hours that children slept, but their sleep quality as well; children who kept their electronics off were consistently more likely to get "excellent" sleep than those who kept them on.

Why is this important? While we can all benefit from a good night's sleep, the issue is especially relevant to teens, who tend to get insufficient amounts of sleep. According to the American Academy of Pediatrics, 87% of U.S. high schoolers get less than the recommended 8.5 to 9.5 hours of sleep, with seniors getting less than seven hours on average. And this has a real effect on schoolwork, with 28% of high school students reporting that they fall asleep at school at least once a week.

And given that around 80% of young people fall sleep with their phones by their beds, the sudden burst of light you get every time you get a text or an alert is probably not helping with sleep.

So if you really want to get some refreshing sleep, put your phone away for the night and use an old-fashioned alarm clock instead. It might feel weird to not have your phone at your fingertips, but your body will thank you in the long run.