Debra stared at the computer until her eyes went blurry. She closed them and shook her head. Why couldn’t she concentrate? Pulling out her smartphone, she checked her Facebook page. Funny. Her friend had posted a picture of her daughter making a snowman. And there was another cat video. Debra had to watch.

Ten minutes later, she put the phone down and got up to get yet another cup of coffee. She was never going to get anything done this way. Maybe caffeine would help.

It worked for a while, but an hour later, Debra was back on her phone again.

Sound familiar? You may be inclined to believe that like many of us, Debra is just addicted to social media. But recent studies suggest it may not be that simple.

In fact, Debra’s constant checking of her Facebook status could be a sign that she’s missing out on something very important to her health: sleep.

Late-Night Use of Smartphones Toxic to the Brain

You’ve probably heard that overuse of our gadgets —smartphones, tablets, and computers—can negatively affect our health.

According to the PEW Research Center, nearly two-thirds of Americans now own smartphones—up from about one-third in 2011. A mobile consumer report stated that a startling 71 percent (nearly three-quarters) of us sleep with them.

They’re either in the bed with us, on the nightstand, or in our hands while we sleep. Of course, that makes them the first things we tend to in the morning—even before our significant others, according to a third of survey respondents.

This trend is more dangerous than we may have thought. According to Dr. Dan Siegel, clinical professor of psychiatry at the UCLA School of Medicine, the screens on our gadgets expose the eyes to a stream of photons that tell the brain to stay awake. As we check emails and Facebook late into the night, we’re telling the brain not to secrete melatonin (the sleep hormone), as it’s not time to sleep.

Let’s say we finally get to sleep at 1:00 in the morning, and we wake up at 6:00 a.m. Dr. Siegel says we’re cutting short the brain’s “clean-up” time, when it usually flushes away toxins that collect during the day. If we don’t get 7-9 hours of sleep, those toxins remain there, potentially causing problems later on.

We’re likely to suffer from:

• Inattention—inability to focus
• Memory impairment
• Lower ability to problem-solve
• Whacky insulin levels—encouraging us to eat more, which can lead to weight gain
• Toxic effects on brain cells

Blue Light is the Enemy

Indeed, smartphone and other screens emit blue light, which suppresses melatonin, the hormone that sinks up our sleep times with our circadian rhythms. When all is well, melatonin levels increase at night, encouraging sleep. But if we’re using our gadgets late at night, we suppress melatonin.

Researchers found this to be true in a 2013 study, when they asked people to use their tablets for two hours before bed. Those who wore goggles that filtered the blue light had higher levels of melatonin than those who used gadgets without wearing the goggles.

A 2015 study found that the repercussions were even worse. In addition to suppressing melatonin levels, using light-emitting electronic devices before bed prolonged the time it took to fall asleep, delayed the circadian clock, and reduced the amount of time that participants spent in REM sleep—that most important type of sleep during which brain and body restore themselves.

When we reduce melatonin before bed, we not only disrupt that night’s sleep, but subsequent nights’ sleep as well. According to a Harvard study, when blue light suppressed melatonin, it shifted circadian rhythms by about three hours. Other related studies indicated that such shifts were linked with prediabetes, while lower levels of melatonin have even been associated with an increased risk for cancer.

Of course, the most obvious issue here is that using these gadgets at night—and sleeping with them—significantly effects sleep. According to a recent study, the danger of lack of sleep could be even worse for women than for men.

The Life-Changing Effects of Sleep Deprivation on Women

Researchers from the United Kingdom questioned over 4,600 participants between the ages of 35 and 55 years and examined data over a three-year period. In addition to using questionnaires, the researchers measured health outcomes during a screening examination.

Results showed that women who got less than the recommended eight hours of sleep at night had a higher risk of heart disease and heart-related problems than men with the same sleeping patterns. They also had higher levels of high-sensitivity C-reactive protein (hs-CRP), which is a marker for future cardiovascular disease. Women who got less than five hours of sleep per night had significantly higher levels of this marker in their blood.

You’ve likely heard that lack of sleep is connected to a number of health problems. A 2007 study, for instance, showed that too little sleep could more than double the risk of death from heart disease for both men and women.

Not getting enough sleep can also affect how we feel, emotionally. According to a recent 2015 study, fatigue compromises the brain’s ability to regulate emotions, leaving us feeling cranky or grumpy. We lose our ability to tell what’s really important, and are more likely to blow up over small things.

But many of us struggle to get the sleep we need. Turns out that one thing we absolutely must do is get the gadgets out of the bedroom.

Your boss will likely thank you. New research from Michigan State University showed that people who used their smartphones after 9:00 p.m. were more tired and less productive the next day at work. Further, smartphones created a greater negative effect than watching television at night.

So if you’re excuse is, “I have to get this done for work,” think twice. You’re likely to be more productive at your job overall if you give the gadgets a rest.

What it Means When You’re Constantly Checking Facebook

Back to Debra. She probably already knows that using gadgets late at night can disrupt her sleep. If she’s read this article, she now knows that it can sabotage her work the next day, too.

What she may not know is that her compulsion to check Facebook may not be about addiction—it could be an indication that she’s not getting enough sleep.

Such were the findings from a recent 2016 study. Researchers from the University of California found that participants who were suffering from a lack of sleep were more likely to be distracted, and that turning to Facebook was the preferred way to deal with it.

For the study, scientists collected data from 76 undergraduates—34 males and 42 females—for a week. They found a connection among the following three things:

1. Chronic lack of sleep
2. Worsening mood
3. More Facebook checking

“There have been lots of studies on how information technology affects sleep,” said lead researcher Gloria Mark. “We did the opposite: We looked at how sleep duration influences IT usage.”

That a lack of sleep can decrease our ability to focus is nothing new. A 2007 study, for instance, found that sleep deprivation, “first and foremost,” impairs attention and working memory, and also affects long-term memory and decision-making. The United Kingdom’s National Health Service agrees, stating that lack of sleep worsens mood and makes it difficult to focus, and also puts you at risk for obesity, heart disease, and diabetes, as well as shortening your life expectancy.

Now we have new ways to tell if we’re not getting enough sleep. Even if you don’t feel sleepy—or no more sleepy than usual—if you find yourself constantly checking Facebook, that could be a sign that you need to get to bed earlier tonight.

Tips to Increase Your Odds of Enjoying a Good Night’s Sleep

Technology is advancing at a steadily increasing rate. Women are doing a great job of keeping up for the most part, but when it comes to our smartphones and other gadgets, we have to start applying some restrictions.

Here’s hoping you’ll adapt these recommendations, to protect your health and your sanity!

• Turn all smartphones, tablets, and computers off at least two hours before bedtime.
• Keep all gadgets, including televisions, out of the bedroom.
• Avoid using e-readers at night—choose a print book before bed, or a tablet that isn’t lit from within.
• Keep all lights low at least one hour before bed—it stimulates your brain to release melatonin, which will help you sleep.
• Use red light in your nightlights—it is least likely to suppress melatonin or disrupt your sleep.
• Expose yourself to bright light during the day, which helps improve mood and alertness, and increases nighttime sleepiness. Outdoor light is best, but indoor “daylight” bulbs can help as well.

via Focus, Fatigue, and Facebook: Why You Just Can’t Concentrate