How long can you stay awake? The truth about losing sleep
You already know that sleep is important.
You may have heard that the CDC (Centre for Disease Control and Prevention) recommends that all adults over the age of 18 should try to get at least 7 hours of sleep each night.
However, getting that regular dose of slumber every night is easier said than done.
Sometimes, we’re kept awake by problems like stress and anxiety. Other times, we actively try to stay awake because we need more time to work on something, like a project for school.
If you’ve ever spent a night staring at the ceiling or trudged through a morning at work after only a couple of eyes of shut-eye, you might have found yourself asking, “How long can you stay awake?”
Perhaps you’ve even asked, “How long can you go without sleep without facing serious consequences?”
The good news is that we can answer both of those questions right here.
The bad news? You might not like what you read.
How long can you go without sleep? The science
How often have you tried to convince yourself that one all-nighter isn’t going to affect your health?
Sure, you’re going to feel a little groggy the next day, but you’ll catch up on sleep later — maybe when you’ve got a day off from work, or you’re relaxing on the weekend.
It turns out that the human body doesn’t actually work like that.
The truth is that every hour you go without sleep has an impact on your health and overall wellness.
Additionally, because all of us have different needs when it comes to snoozing, it’s hard to know what your limit is when it comes to answering “how long can you stay awake”.
One study into sleep deprivation does give us a slight insight into how long a human being might be able to survive without sleep. Randy Gardner currently holds the world record for losing sleep, with a total time spent awake of 11 days and 25 minutes.
However, there are some problems with using Gardner as a benchmark. Researchers admit that after a few days, Randy was having almost constant “microsleep” periods to help his brain survive.
This meant that his brain was actively shutting down to preserve energy, even if he didn’t appear to be going to sleep.
Even if you didn’t count micro-sleeps and agreed that 11 days was the limit for losing sleep, going any period without adequate rest isn’t great for your health.
In 1959, a radio presenter named Peter Tripp broadcast his show from the middle of Times Square for a total of 201 hours to raise money for a children’s foundation.
By the third day in his journey, Tripp was vividly hallucinating, cursing, and acting aggressively towards people around him. Tripp’s family maintain that he was never quite the same after the experiment.
Why do we need to sleep? Is it more important than food?
The most that scientists have been able to accomplish is suggesting a few theories, like that we need sleep to clear the brain of waste and reset bodily functions.
Studies also show that regular sleep allows for the proper functioning of the immune system. At the same time, adequate amounts of sleep assist in supporting the growth of white cells, which can help with recovering from injuries and disease faster.
We also know that sleep is essential to keep the brain working properly. Since the human body can’t live without the brain, it makes sense that sleep would be crucial to our overall health.
When you sleep, your brain sorts out all the information that you’ve collected during the day, creating long-term and short-term memories.
If the problem persists for long enough, the effects can be catastrophic, making it impossible for you to recover from illnesses and increasing your chances of early death.
Unfortunately, human beings today don’t have the right perception of sleep.
We know that it’s important, but we don’t treat it with the same respect as other crucial fuels like food and water. For instance, you might decide that you can pull an all-nighter if you want to go to a gig with your friends.
However, you wouldn’t suddenly decide to stop eating or drinking for a day.
Surprisingly, the human body seems to respond more negatively to losing sleep than losing food or water. Evolution has equipped our species to go up to a week without water, and three weeks without food.
However, you’ll start to see the side effects from losing sleep within 24 hours. Within a couple of days of staying awake, you wouldn’t be able to function.
Losing sleep: What to expect in the early days
The answer to “how long can you stay awake physically?” is complicated. It depends on factors like how many hours of sleep you usually need to feel rested and healthy on the average day.
Different people need different amounts of sleep to function.
Additionally, if you have pre-existing medical conditions, like problems with your heart or cognitive functioning, then a lack of sleep could be more dangerous.
A person with a heart condition or a problem with their immune system might perish before they reached the 11-day record of Randy Gardner, simply because they wouldn’t be able to recover if anything went wrong with their body.
As mentioned above, most people start to experience the effects of losing sleep within 24 hours.
The CDC tells us that staying awake for 24 hours creates a mental state that’s similar to having a blood alcohol content of 0.10%.
Obviously, you shouldn’t drive after a night without sleep, and you might not be able to trust your memories or thought processes either.
A 2016 study into young adult men learned that these men were had a higher chance of recalling false memories when they had been awake for more than 24 hours.
Additional research has also found that people who stay awake for 24 hours or more often have higher levels of something called beta-amyloid in their brains.
Beta-amyloid is the stuff that causes cells in your brains to break down. It’s supposed to be cleared from your head after sleep. If it isn’t, then you could have a higher risk of suffering from Alzheimer’s disease.
If you stay awake for 36 hours (a day and a half), then the side effects get even worse.
You might struggle from reduced eye movement function, which means that you can’t focus on anything in particular.
Additionally, you might not be able to speak properly either. Researchers have found that subjects suffering from losing sleep for 36 hours spoke in “bursts” rather than full sentences.
On top of that, like any kind of sleep loss, being awake for 36 hours means that you’re going to see a reduction in your reaction times and orientation. People with this level of sleep deprivation often stumble through the world in a haze.
Sleep deprivation psychosis and other major problems
According to some studies, the maximum amount of time that you can stay fully awake may be capped at 48 hours. That’s because after you’ve been awake for 2 days, you’re going to start trying to protect yourself subconsciously.
After 2 full days, your brain will be more vulnerable to micro-sleeps. These are small periods where your brain will shut down for a few seconds, even if you seem to be still awake.
If you’re wondering, “how long can you stay awake completely?” then as soon as you start experiencing micro-sleeps, then you’re no longer in the competition.
The more you stay awake, your brain will fight back, hitting the snooze button on certain functions while other parts of your body remain awake.
Physically, you may be able to continue acting as though you’re awake after 48 hours without sleep, but your symptoms will just get worse.
For instance, if you managed to stay awake for a full 72 hours, then you’d be likely to suffer from symptoms ranging from increased heart rate to negative mood.
One study conducted in 1984 found that six men deprived of sleep had a change in their urine habits.
The urine collected from the men had decreased electrolytes and glucose, leaving the researchers to conclude that sleep deprivation disrupts metabolic functioning.
Additionally, a study of rats found that after 72 hours, the circadian clock gene and oxidative stress levels of the subjects changed.
By the time you reach day four, your brain starts to go into meltdown mode. Even with micro-sleeps to protect certain parts of your mind, you’ll be exposed to sleep deprivation psychosis.
In other words, most people start to hallucinate after three or four days awake.
Your brain will be conducting “micro-sleeps” more often than ever, and you may have a hard time separating reality to what you see in your head.
To make all this even worse, the question “how long can you stay awake?” becomes even more complicated when you consider the long-term impact of going without sleep.
For example, you might be able to stay awake for several days, but the long-term effects on your health and functioning could mean that you’re never the same again.
If your sleepless nights become a chronic problem, then you might end up suffering from a higher risk of depression, severe mood swings, heart disease, mental illness, and even asthma attacks.
The CDC indicates that people who regularly sleep fewer than seven hours a day are more likely to report a range of chronic health conditions, such as coronary heart disease or heart attack.
In other words, losing sleep for just one hour a night could mean that you’re more likely to die from a stroke, COPD, cancer, or a heart attack than people who have the same life as you in every other way.
It’s worth noting that while losing sleep can’t kill you on its own necessarily, it can make you a lot more susceptible to potentially fatal issues, ranging from depression, to chronic kidney disease and diabetes.
Going without sleep is like chopping a kidney out of your body. Your body will try to make do with what it has, but you’re going to be more exposed to risk than other people.
Additionally, losing sleep can also mean that you make more dangerous decisions, and expose yourself to greater threats. The National Highway Traffic Safety Administration found that 90,000 vehicle crashes in 2015 were caused by sleep-deprived drivers.
Since sleep also regulates your immune system, you might be unable to fight off basic diseases that your body would otherwise be able to protect you from if you’re constantly losing sleep.
Think back to the last time you had a cold. You might have noticed that you wanted to sleep more often during your illness.
That’s because your body takes part in a lot of vital healing processes when you’re asleep, including producing white blood cells that fight off infection.
Without sleep, there’s nothing to help you heal from various elements, and nothing is stopping you from getting sick in the first place.
Experimenting with how long you can go without sleep might not kill you directly, but it will open the door for everything from diabetes to the common cold to finish you off.
Can you make up for lost sleep?
By now, you’re probably wondering whether the outcomes of going without sleep are just as bad if you resolve to catch up on the hours that you’ve missed.
After all, surely you don’t have to worry about sleep deprivation if you’re planning on making up for the hours you missed on Wednesday with a lie-in on Sunday, right?
Unfortunately, that’s not necessarily the case.
Scientists have been asking, “can you make up for lost sleep?” for a while now, and the results have been a little confusing.
Some experts believe that you can repay some of your sleep debt by going to bed slightly earlier than usual each night for a few days. Others think that there’s no way to recover lost sleep at all.
One thing that seems certain is that you can’t experiment with the question “how long can you stay awake” then make up for your sleep loss on a Saturday.
Sleeping too long on the weekend could compound the health problems that you’ve developed from sleep deprivation.
A study in Current Biology found that when a group was given extra time to sleep after being sleep deprived, they did see some minor improvements. However, when they returned to their regular schedule, the benefits disappeared.
What’s more, the findings in the study also discovered that subjects who were allowed recovery sleep on the weekends had worse muscle and liver insulin sensitivity than their counterparts. The scientists concluded that weekend sleep recovery isn’t an effective sleep-loss counter measure.
If you are planning on making up for lost sleep in the future — perhaps because you’ve lost sleep through something that you couldn’t control, like insomnia, it’s going to take time. You won’t be able to top up your rest on the weekend and instantly feel better.
Instead, you’ll need to make slight adjustments to your routine.
For instance, you might consider going to bed half an hour earlier than usual for a couple of weeks. This won’t throw your current ritual too far out of whack, but it will allow you to get some extra rest.
Additionally, trying to make up for extra sleep isn’t going to be helpful if you allow yourself to simply go without sleep again soon after. You’ll need to consistently plan for adequate sleep, by figuring out how many hours you need to feel your best.
Once you’ve calculated the number of hours that you need, you’ll need to stick to your routine religiously to ensure that you don’t suffer from losing sleep again.
Going without sleep: It’s not a good idea
We’ve all wondered, “how long can you stay awake?” once or twice in our lives. But we’re here to tell you that experimenting with sleep loss is a dangerous thing — and something that no-one should try.
There’s a reason that your brain and body naturally attempts to ensure that you’re getting the right amount of sleep each night. Without adequate slumber, it becomes increasingly difficult for us to function.
Even a day or two of sleep deprivation can make it impossible for you to behave normally in your day-to-day life. Experts suggest that losing sleep can be worse than losing out on adequate nutrition.
The good news? It looks as though it’s almost physically impossible to stay awake for days at a time.
If you’re worried that you’re going to die because you can’t get enough sleep due to insomnia, you don’t need to panic. Your brain and body have fail-safes built in that will ensure that you get to sleep eventually.
Ultimately, no matter how hard you try to stay awake, your body will end up forcing you into sleep.
In the meantime, if you’re worried about the outcomes of sleep deprivation, the best thing you can do is speak to your doctor.
They’ll be able to conduct a sleep study that gets to the bottom of why you’re struggling to sleep, and how you can overcome your issues.