How many hours of sleep do you get every night? If your answer was less than seven hours or if you asked, “what is sleep?” then you are sleep deprived. The National Sleep Foundation recommends that adults (aged 18 to 64) get seven to nine hours of sleep each night. Yet, most of us don’t get that much sleep, thanks to our busy lives (and the technological devices that we can’t seem to put down at night). But, we love sleep-- it’s one of the most mentioned topics in memes, along with food. And it’s a good thing we love sleep, too, because it’s absolutely essential.
There are so many beneficial things that happen while we sleep. For example, during sleep, your brain forms new pathways to help you remember the important information from the day and your heart and blood vessels heal. Sleep is also essential for your immune system, which defends your body against foreign substances like harmful viruses and bacteria.
So, as you can imagine, a lot of things go wrong when you don’t get enough sleep. And the scariest part is that not all of these things are reversible. We’re here to let you in on 15 things that could happen. After reading these, you’ll definitely want to turn off your computer or phone and grab the nearest pillow.
15 Emotions Become Heightened
Have you ever gone absolutely nuts on someone for no real reason (or vice versa)? Perhaps sleep deprivation was to blame. When you’re sleep deprived, your emotions actually become heightened. That’s because sleep is vital for a part of your brain that helps regulate emotions (the frontal cortex). The amygdala is also another part of the brain that plays an important role in emotions. It controls fear and anger (AKA the fight or flight response). So, when you don’t sleep, the frontal cortex becomes disconnected from the amygdala and your emotions go out of whack.
This actually makes a lot of sense when you think about it, as many psychiatric and emotional disorders involve sleep deprivation. Several studies have also found that REM (Rapid Eye Movement) sleep is essential for improving regulation of mood in clinical depression.
14 Reaction Time Decreases
If you’ve been noticing that you suck at video games lately, it may be because you’re spending too much time playing them and not enough time sleeping. Yes, sleep deprivation slows your reaction time (something that’s very important in video games). On a more serious note, having a delayed reaction time is very dangerous when you’re driving or operating heavy machinery. So now you understand why those medicines that make you drowsy come with the warning label. It’s so serious, in fact, that one study even found that being tired while driving was nearly as dangerous as drinking and driving! That’s pretty scary, huh? You may want to consider getting a designated driver, not only for nights out on the town, but also for nights that you stay up studying for finals.
13 In Males, "His Swimmers" Production Decreases
If you’re a guy, you better listen up. You need to sleep more if you plan on having kids one day (and we mean actually sleep more, not sleep around or sleep with someone). Why is this important? Well, a 2013 Danish study published in the American Journal of Epidemiology found that men who experienced a lot of sleep disturbances had 29 percent less sperm in their semen than those who slept eight hours each night. Why? They’re not quite sure, but it may have something to do with sleep affecting testosterone levels. Or, it may have something to do with the fact that men who sleep less have overall unhealthier lifestyles (they weighed more, smoked more etc.). Whatever the reason, it’s better to be safe than sorry, right?
12 The Libido Decreases
While we’re on the topic of sperm, we should also mention that sleep deprivation decreases the libido (so you may not even notice the whole “less sperm” situation). A study published in the Journal of the American Medical Association in 2011 found that men who slept five hours a night for one week were unable to concentrate, had low energy, and had low interest in sex. This makes sense, though. How many times were you sleep deprived and wanted to do anything other than sleep?
But, exhaustion may not be the only culprit here. Sleep loss can cause a decrease in sex-related hormones, such as testosterone, too. To give you some perspective, the male subjects in the study also displayed a 10 to 15 percent drop in testosterone levels over the course of one sleep-deprived week, which is actually more significant than it sounds.
11 In Females, Her Period Gets Messed Up
And for all you girls out there, sleeping messes with your cycle. Again, you may have noticed that during exam time, or some other time that you were really stressed out and didn’t sleep much, your period was late. Or, if you work irregular shifts, your period may be inconsistent. There’s a good explanation for that.
Many studies show a direct connection between the sleep clock in the body, melatonin levels and fertility hormones, all of which affect menstruation. When you don’t sleep enough, or sleep at different times each night, your body’s internal clock gets confused. This affects melatonin levels (which affect reproduction) and reproductive hormones. So, next time your monthly gift is late, check your sleeping patterns before freaking out.
10 Memory Deteriorates
We’ve probably all experienced this one. You go to work or school, totally sleep deprived, and keep forgetting where you put your pen, what you were supposed to have done by the end of the day etc. It’s a classic symptom of sleep deprivation—memory loss.
Sleep is important for consolidating memories (i.e. making them stick). That’s why your parents and teachers always told you to get enough sleep before your big test. And that’s also why you remember the stuff you read right before you fall asleep. Your brain actually does a lot of work while you sleep. But, when you don’t sleep enough, it leads to a loss of connectivity between neurons in the hippocampus, a region of the brain associated with learning and memory.
9 Immune System Is Suppressed
When you’re sick, what do you usually want to do the most? Curl up in your bed and sleep, right? There’s a reason for that: sleep helps your immune system to fight off illnesses. So, when you don’t sleep enough, you’re putting yourself at risk for getting sick. That might actually explain why a lot of people get sick around exam season, combined with the impact of stress on the body.
So, how exactly does sleep deprivation suppress your immune system? Well, it may decrease production of cytokines, which are basically molecules that send out a signal to other cells that the body needs help. In addition, infection-fighting antibodies and cells are reduced during periods when you’re sleep deprived. Being chronically sleep-deprived also increases your risk for serious illnesses, such as cardiovascular disease and diabetes.
8 Appetite Increases
If you’re like most humans, you’ve pulled an all-nighter. And during this all-nighter, what did you do? Probably some work or stayed up socializing, whether in person or through a screen, and ate… a lot. We’re talking about cereal, chips, the leftovers from dinner and whatever else you could lay your hands on. But, why do you feel so hungry when you don’t sleep?
Well, your body produces more ghrelin, the hormone that causes you to feel hungry. And it doesn't produce enough leptin, the hormone that makes you feel full. So, you end up eating more than you normally would. One study actually found that sleep-deprived participants ate an average of 1,000 extra calories at night! And no, they didn’t eat less during the day to make up for it. If you make this a habit, it could lead to obesity.
7 Thinking Is More Difficult
If you’ve ever been to college, or were a real keener that pulled all-nighters even in high school, you’ve likely experienced this one. It’s four a.m. and you’re reading your book when suddenly, you hear footsteps in the hallway and they’re so damn loud! Or, you’ve pulled your all-nighter and are ready to take on the test, so you step outside and OMG, it’s never been so bright out!
Hate to break it to ya, but those footsteps were never that loud and it was just as bright out as it usually is. What happened there? Well, your sleep deprivation messed up your ability to process sensory information and that includes visual, auditory, tactile, olfactory (smell) and taste. Basically, when you’re sleep deprived, your tolerance for cold (and heat) will be lower and you won’t be able to tell which out of two sounds came first. Yeah, it’s pretty freaky.
6 Your Appearance Suffers
Okay, who hasn’t resembled a zombie, at least once, due to lack of sleep? It’s safe to say most of us have been there, done that. But, if you are one of the strange people that go to bed at nine o’clock every single night, without fail, and wake up well-rested, then you’ve at least witnessed someone who looked like a zombie after a terrible night’s rest. So, this should come as no surprise.
When you don’t sleep—to put it bluntly—you end up looking like crap. There are the bloodshot eyes, dark circles around the eyes, dull complexion and maybe even a pimple or two. Why? Well, when you don’t sleep, the flow of blood to the tiny vessels close to the skin’s surface slows, leading to pale skin and puffy eyes. Your skin’s moisture levels and complexion’s pH levels are also decreased, creating dry and uneven skin. Hey, they don’t call it “beauty sleep” for nothing.
5 Sense Of Humor Disappears
Have you been finding everyone to be not funny lately? Sleep deprivation may be to blame. Or, maybe those people you hang around really aren’t funny.
But, seriously, jokes are actually pretty complex. They require language comprehension, memory, attention and divergent thinking (and yes, it’s just like in the movie, Divergent). When you don’t get enough sleep, however, the inferior frontal gyrus part of the brain is affected. This is one part of the brain responsible for language comprehension, including humor comprehension (connecting all the dots in a witty conversation or joke). It also affects the prefrontal cortex, which is responsible for attention, memory and divergent thinking. So, if you often say “I don’t get it” after a joke, your inferior frontal gyrus and prefrontal cortex (along with the rest of your brain) probably needs some rest.
4 Your Voice Is Weakened
You know the feeling—you’re so tired that you can’t be bothered to express your enthusiasm, so you go on talking like a robot-- completely monotonous. Everyone around you knows not to bother you when you’re speaking in this signature “tired voice.” But, what exactly causes it (besides your complete lack of enthusiasm for anything that doesn’t involve a bed or some pillows)? Well, when you’re tired, the muscles in the throat that govern the sound of your voice are not as well controlled. In other words, the mechanisms for speaking, the ones that coordinate your mouth and tongue, temporarily break down just like everything else does when we’re sleep deprived.
3 You Just Look Sad
What’s worse than someone telling you that you look tired? Someone telling you that you look sad when you’re not. Well, maybe you are a bit sad because you didn’t get enough sleep, but that’s not the main reason you look sad. When you’re sleep deprived, your face literally droops, especially around the eyes and mouth. This is because controlling your muscles requires a level of alertness that just isn’t there when you’re sleep deprived. In addition, the puffy eyelids and dark circles add an extra gloomy look to your face. So, instead of walking around looking depressed and having people constantly telling you to cheer up, get some sleep!
2 Hallucinations Happen
If you’re staying up to binge watch some series on Netflix and suddenly you start seeing the characters in your living room, it’s time to hit the sack. Visual hallucinations don’t just occur in people with mental illness; they can occur in those with extreme sleep deprivation, too. Like, you’d really have to be tired, we’re talking no sleep for several days in a row. Why some people willingly subject themselves to this, we’ll never know. For others, though, there’s no choice. If you suffer from insomnia, you’re more likely to experience this symptom. It’s kinda scary because the symptoms of sleep deprivation can really mimic those of mental illness. In fact, one study found that a small percentage (2%) of people who were sleep deprived for about 100 hours experienced temporary conditions that were similar to acute paranoid schizophrenia. The good news is that, with adequate sleep, the hallucinations disappear.
1 Brain Damage Occurs
Okay , so you might be thinking that most of these things that can happen when you’re sleep deprived are too terrible, especially since many are only temporary. But, it’s about to get real.
Sleep deprivation can actually cause brain damage… and it’s irreversible! So, what exactly happens? Well, neurons living inside the brain region known as the locus coeruleus (LC) slowly begin to die. These neurons play a role in energy production and they also take over when your prefrontal cortex shuts down. Not only that, but research has found that people suffering from sleep deprivation also had more cortical shrinkage in their brains! What may be even more surprising is that sleep deprivation has been linked to Alzheimer’s Disease. A study showed that mice that slept less, due to light disturbances, had an increase in the amount of tau protein that became phosphorylated and formed tangles, which are a characteristic of Alzheimer’s Disease. There have also been implications that sleep deprivation triggers Alzheimer’s in other ways, as well. Suddenly, watching that entire TV series or clubbing ‘til dawn (or even staying up to study) doesn’t seem so important, right? Save your brain and go to sleep!