What Happens When You Only Sleep For 6 or Fewer Hours Per Night?

By Isadora Baum

If you think that pulling a few late nights in a row isn't going to hurt you, you're wrong. It turns out that skimping on much-needed shut-eye can wreak havoc on your health and immune system, and it could put your body under serious stress that can affect other areas of your life, such as work and relationships. (And no, while napping does have its benefits, it doesn't make up for lost sleep.)

Sleep
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So, what can happen exactly? Why might it be so important to get between 7 and 8 hours of sufficient snooze time nightly? Here are a few things that can happen if you're not getting the right amount of sleep your body needs to function and be productive during the day.

It Hurts Your Metabolism

Even a single night of sleep deprivation can significantly affect physiological function. "It can impair immune function and cardiovascular health," says Kimberly Fenn, Reverie Sleep Advisory Board Member and Associate Professor of Psychology at Michigan State University, as it puts the body under serious stress.

"Interestingly, sleep deprivation also affects eating behavior and glucose metabolism. Specifically, levels of ghrelin, a hormone that signals hunger to your body, increase, whereas levels of leptin, a hormone that signals satiety, are reduced. Thus, after an all-nighter, you are more hungry than normal and your body feels less full than if you were not sleep-deprived," she says.

"In addition, the body is in a state of impaired glucose tolerance, meaning that your body is less able to metabolize glucose, [which is] similar to being a pre-diabetic state," she adds.

Sleep
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It Can Put You in Danger

"Being tired is one potential symptom of sleep deprivation, but actually not being tired is one of the major risks. If you don't sleep all night, your body hasn't healed or refreshed, so your brain functions similarly to how it would when you're legally drunk," explains Dr. Benjamin Smarr, National Institutes of Health Postdoctoral Fellow at UC Berkeley and Reverie sleep advisory board member.

Here's how it works. "In the morning, your circadian sleep drive runs out causing your circadian clock to switch to promoting wakefulness – meaning you feel like you get a second wind. In this wide awake, yet unrested, state is when many people have accidents because they overcompensate for what their body and mind can actually handle. In fact, far more harm is done annually from sleep deprived driving than actual drunk driving," he says.

Plus, it also compromises your immune system, making you more prone to sickness. This means that you're more susceptible to catching a cold, which can increase the number of "sick days" you'll need off from work.

Sleep
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You're Not as Sharp

Your brain won't be firing as usual. "After a poor night's rest, don't expect to be a stellar—or even decent—number cruncher. In one study, subjects who had gone 35 hours without sleep performed significantly worse than their well-rested counterparts on arithmetic problems and had much less brain activity in the prefrontal cortex," explains Martin Rawls-Meehan, CEO and co-founder of Reverie.

Your Decision Making Skills Are Off

It's hard to think clearly when you're short on sleep. "When you're sleep-deprived, your prefrontal cortex doesn't work well, which impairs a whole host of complex functions. Chief among them is the ability to make decisions," says Rawls-Meehan. "Part of the impaired ability to make decisions likely has to do with the fact that it's a lot harder to focus when you're sleep-deprived," he explains.

You also might have trouble picking up on clues. "The prefrontal cortex is also responsible for moderating social behavior. When this part of your brain isn't firing on all cylinders, you're less able to make jokes or appreciate humor," he says.

You Might Be Grouchy

You'll have a hard time smoothing things over with others and regulating your emotions, when you're missing out on valuable sleep. "In fact, you're more likely to exacerbate the situation, as those who are sleep-deprived are more inclined to bicker and express negativity," when in the midst of a heated argument, says Rawls-Meehan.

Lack of sleep can lead to mood swings and an inability to keep your calm in light of stressful situations.