Sleep. It’s the place where we’re all Vikings. Or donuts. Whatever it is that happens to you in your dreams. It’s the most horizontal you can be in a day, and it’s usually pretty relaxing. Man, who doesn’t love a good sleep? But what happens if you don’t get enough of it?
Everyone’s probably pulled an all-nighter at some point in their lives, whether for work or pleasure. You stay up all night, the morning comes around, you just figure “oh well. Been up this long, might as well stay up for a whole day.”
At some point, though, that gets old. Usually we don’t go beyond a day or two at the most. And it’s fairly well known that at some point, you’ll start suffering some ill effects from not getting sleep.
The mechanics of how this works are not as well known, however. Nor is it always really clear exactly what goes wrong when you don’t get enough sleep, or just how bad things can get for you. So let’s take a look at what medical science tells us about sleep, how much you need, and what you’re risking if you don’t get enough.
How Much Sleep Do You Need?
Most of the world seems to be based around the idea that we need 8 hours of sleep per night. We’ve divided our 24 hour periods into 8-hour segments as adults in the western world. You work for 8 hours you sleep for 8 hours and the other 8 hours is when you fit in everything else you need to do.
Realistically, it’s not always that simple. Medically speaking, as an adult, you should be getting at least 7 hours of sleep per night. The younger you are the more sleep you’re going to need. Babies are out there living the high life getting a recommended 16 hours of sleep per day. They’re basically cats until they’re a year old.
Hours of sleep is not a blanket thing, however. People are different and you can’t say specifically that everyone needs this many hours. Some people can function on less sleep, and some people are going to need more. In general, it’s the quality of your sleep that you need to be concerned about, as opposed to how much of it you get.
Sleep quality is concerned with how well you slept, rather than how long. Some nights you hit the pillow, you’re out like a light, and you wake up with your alarm in the morning. Ideally, you feel refreshed, and ready to start your day. That was a good, quality night’s sleep.
On the other hand, sometimes you lay down and you stare at your ceiling, you stare at the display on your clock; you toss and turn; you wake up three times to go to the bathroom, and in the morning you somehow feel worse than you did when you went to bed the night before. You could have had the exact same number of hours, but that was not quality sleep.
If you’re getting good sleep, you probably don’t need more than 9 hours as an adult. That’s not to say anything bad is going to happen to you if you sleep from 12:00 to 12:00 on a Sunday, it’s just that you probably won’t get a ton of benefit from those extra hours.
How Long Can You Go Without Sleep?
In 1986 a man named Robert McDonald broke a world record by staying awake for nearly 19 consecutive days. His total hours was just below 454. That’s a hell of a long time to be awake and it’s generally not recommended. He had to be monitored the entire time and, as you might expect, people had to observe him non-stop to make sure he didn’t fall asleep.
You can start feeling the effects of sleep deprivation after as little as 24 hours. Sleep deprivation has been likened to drunkenness. Going without sleep is like having a blood alcohol level of 0.1%. in most places in the world, that’s above the legal limit. That means you’re going to be suffering some cognitive impairments, slow reaction time, brain fog, all that stuff. The symptoms are all very similar to drunkenness.
In addition to those various impairments, your stress hormone production actually begins to go up. So you’re going to start producing more cortisol and adrenaline. This is because your body knows you’re lacking sleep and trying to help you out.
By 36 hours of not having sleep, you’ll start having physical symptoms. They may not be obvious from the outside, but you’ll be suffering from hormone imbalances. Your appetite and body temperature can suffer, and your mental state will continue to deteriorate. Irritability is a very common symptom.
After two days of not having sleep, you can start experiencing something called microsleep. That happens when you’re still trying to stay awake but your brain has had enough of your shenanigans and actually shuts off for several seconds. You may not even notice it happens, and it’s like a little reset switch went off for less than a minute.
You’ll begin to notice some serious symptoms within three or four days of not sleeping. This can include hallucinations, paranoia, and even psychosis. Interestingly, there isn’t a ton of research on what happens when you stay awake this long because it’s not considered ethical to make someone do it. At this point, sleep deprivation is essentially torture, and your average doctor doesn’t want to do that to a patient. At least not in a way that would allow them to write about it in a scholarly journal after the fact.
We do know that your hallucinations can become longer and more complex at this level. It’s hard to speak without slurring, even walking without stumbling around is difficult. And by 120 hours you can experience psychotic breaks with reality.
But, just like not everyone needs the same amount of sleep, not everyone’s going to have the same experiences. The world record holder for sleep deprivation suffered very few ill effects from his experience, so your mileage may vary. As a general rule though, you probably don’t want to try it yourself.
Sleep Deficiency and Deprivation
A lack of proper sleep can manifest itself as either sleep deficiency or sleep deprivation. The terms are similar enough that you might want to use them interchangeably, but there is a technical difference between the two. Sleep deprivation could be considered more acute while sleep deficiency is more of a chronic issue. Sleep deprivation is one factor or symptom of sleep deficiency.
Additionally, sleep deficiency might involve sleep disorders that affect the way you sleep, the inability to get to sleep when you want to, or consistently poor-quality sleep.
About 1 in 5 people in America get less than 5 hours of sleep per night which qualifies a sleep deprivation. That’s essentially an epidemic. Your bad sleep can be caused by a number of things, some of which are in your control and some of which aren’t.
Sleeping at night can be hard if you take naps during the day. This throws off your natural cycle. Likewise, using devices like phones before bed has been shown to cause poor sleep. Caffeine and other drugs can affect your ability to get good, consistent sleep as well. All of this contributes to sleep deprivation which can spiral into sleep deficiency if it’s allowed to keep happening.
What Happens Physically When You Don’t Sleep
We briefly looked at what happens when you don’t get enough sleep, at least in general terms. Now let’s get a little more specific about what’s going to happen to your mind and body if you find yourself suffering from sleep deprivation for too long.
When you suffer from a lack of sleep, and that doesn’t mean not sleeping at all, that just means not getting the full, proper amount of sleep you need, you can expect that it will affect your mood the next day. There’s a good chance you’re going to be more irritable and experience other negative feelings but you otherwise or shouldn’t be affected by. You’ll also be feeling stress more acutely.
People who did not have depression before developing sleep disorders have nearly double the risk of developing depression as those who don’t have sleep disorders. As many as 80% to 90% of people with depression suffer from insomnia. The effect on your mental health really can’t be overstated.
Poor sleep will also affect both your memory and ability to learn. In fact, your ability to learn new things can be reduced by as much as 40% if you’re not getting the proper sleep. This ironically flies in the face of the idea of a college student pulling an all-nighter to study for an exam, as you’re actually working against yourself at this point.
Just one night of sleep deprivation could affect both your balance and coordination making you clumsier and slower to react during the day. You literally walk differently when you haven’t had enough sleep.
There are also noticeable, physical tolls of not sleeping properly. Your immune system will suffer from a lack of sleep and that means you are more likely to get sick and stay sick longer. Even a simple cold is going to hit you harder and last longer when you suffer from sleep deprivation.
We have probably all seen somebody and thought they looked tired, and there’s a reason for that. You literally look different when you’re not getting enough sleep. You’re more likely to have puffy, red, or drooping eyes. Dark circles, pale flesh, and a drooping mouth were all noted as well. And because sleep affects cortisol levels, a lack of sleep could lead to more wrinkles.
A lack of sleep has also been linked to weight gain. The same regions of your brain that are stimulated by smoking marijuana that can lead to the munchies are stimulated when you don’t get enough sleep. That means you’re inspired to eat more when you sleep less which can lead to obesity.
A lack of sleep later in life can also lead to dementia and Alzheimers. It can also put you at risk of hypertensive heart disease. Basically, sleep deprivation is bad for you across the board. There aren’t a lot of areas of your personal health that are going to improve if you’re not sleeping, but there are plenty that are going to get worse.
Arguably, the most Insidious thing about this is that it’s a game of inches. Each of these things grows slowly. So nothing is affected terribly at first, it’s just many little things chewing away at your overall health to make you feel worse in a way that’s really hard to even notice at first.
Can Lack of Sleep Kill You?
There are two ways to look at this question. If you fail to go to sleep for a long time, it’s not like your body is just going to seize up and you’re going to crap out. Lack of sleep isn’t like a gunshot wound. Lack of sleep has never directly killed anyone that we’re aware of. That said, chronic sleep deprivation can lead to accidents and earlier death. And there is evidence of lack of sleep being lethal to animals.
There is actually a genetic condition called fatal familial insomnia which can develop over time and increase in severity the longer it goes. As it progresses mental and physical deterioration occur, including a breakdown of your body’s autonomic systems. Your ability to regulate your breathing and heart rate can suffer and that can ultimately be fatal to those who suffer from it. This is, of course, different from simply not getting enough sleep and suffering a fatal result.