What Would Happen If You Didn’t Sleep?

What happens if you don’t sleep? Surely, most of us as teens or college students have asked the question, “How long can you stay awake?” at sleepovers or during all-nighters. And we may have tested our body’s own limits in order to find out.

But perhaps we should have been asking a different question: What happens when you don’t sleep, as far as the effects on your body, organs, and systems?

We’ve created a sleep deprivation timeline — based on scientific studies and personal accounts of sleeplessness record-holders including Randy Gardner — showing what typically happens to one’s body after hours, days, and even weeks of no sleep. Spoiler alert: Going without sleep can be pretty alarming!

What Would Happen If You Didn't Sleep

Like this infographic? Share using this link or the embed code below!

Can I Die From A Lack Of Sleep?

Yes, sleep deprivation could kill you, theoretically — though you’re far more likely to die from an accident, stroke, or heart attack first, all of which become increasingly likely the longer you stay awake. For example, Chinese individuals staying up for days to watch soccer have died from complications that arose due to lack of sleep. Because of immune suppression, it’s also likely that one would die from a disease first.

Could one die of lack of sleep alone, in a completely controlled environment? It’s hard to say, but those with the rare and terrifying prion disease familial fatal insomnia typically die within a few months of onset, despite controlled environments or even attempts to force them into a coma.

What Happens If You Don’t Get Enough Sleep?

Here’s a general breakdown of what happens when you go for a while without sleep:

  • As soon as you miss even an hour or two of sleep, you’ve already markedly increased your risk of heart attack and stroke.
  • As you go from missing a few hours to nearly a day, several things happen in sleep-deprivation stages, most immediately a lack of hand-eye coordination, decreased learning, poor mood, and impaired judgment.
  • As the lack of sleep continues, more physiological problems emerge, including hormone swings, immune system suppression, and increased blood pressure.

If you’re wondering, “How many hours without sleep do I need before I start to see these changes?” it really depends on the physiology of the person. But for some people, even a few lost hours can cause massive changes in basic hormone functions, which affects numerous bodily systems.

What Happens If You Go 24 Hours Without Sleep?

Is staying awake for 24 hours bad?

Unequivocally, yes: 24 hours of no sleep is particularly bad, with effects ranging from mild symptoms to severe ones. Not sleeping for a whole day creates a list of problems including:

  • An overall cognitive impairment that resembles someone with a BAC of 0.1% (1)
  • Increased blood pressure
  • Increased cortisol (which causes its own host of problems)
  • Increased thyroid-stimulating hormone (TSH)
  • Increased cytokines (which cause inflammation (2) and a suppressed immune system (3))
  • An overall dampening of all brain cell activity (almost like all of your neurons have slowed down)

What Happens If You Don’t Sleep For Days?

  • At 36 hours without sleep, you’ll see a lack of long-term memory creation. Some people, like soldiers, have even experienced whole days going missing from their memories. You’ll also see more triggering of the flight-or-fight response to stimuli.
  • At 48 hours without sleep, or two days, you’ll start to experience microsleeps (if you haven’t already), along with decreased insulin and several forms of ataxia, such as slurred speech.
  • At 72 hours without sleep, researchers have observed hallucinations, a lack of memory, light sensitivity, and an intensity of previous symptoms such as emotional moodiness. After three days without sleep, most people’s need to sleep will outweigh their need to eat.

What Happens If You Don’t Sleep For A Week?

At the four- and five-day marks, beyond an overall lack of ability to concentrate on anything for more than a few minutes, researchers who have gone without sleep have had very extreme experiences. These include bouts of unpleasant hallucinations, paranoia, and even doubts about their own realities. Peter Tripp’s publicity stunt is particularly of note, as many of his experiences were broadcast live on the air. In one instance, he believed a scientist was an undertaker and ran away from him.

How Long Has Anyone Gone Without Sleep Willingly?

How long can a human go without sleep?

Willing researchers and participants include Randy Gardner (who stayed awake for 264 hours, or 11 days), Toimi Soini, the official Guinness record-holder for going without sleep (who stayed awake for 276 hours, or 11 and a half days), and the unofficial case of Maureen Weston (who reportedly stayed awake for 499 hours, or nearly 19 days).

How Long Can You Go Without Sleep Before You Die?

How long can you survive without sleep?

Allan Rechtschaffen tried to find that answer using rats, but after 32 days, all of his rats were dead.

People in controlled environments with a tangled prion disease called familial fatal insomnia have survived as long as 6 months without sleep.

Based on this very limited research, it seems that out of people willingly going without sleep, the willpower to do so seems to dissolve after about 11 days, but people forced to live without sleep may survive anywhere between three and six months. But it’s likely they would die of complications due to lack of sleep before then.

Has Anyone Died From Sleep Deprivation?

Yes. Michael Corke is one of the most famous cases of familial fatal insomnia, which stems from an extremely rare genetic mutation. His mind couldn’t shut down even despite doctors attempting to put him into a coma. He died in 1993 after going without sleep for six months.

Do You Really Need 8 Hours Of Sleep Each Night?

Yes. From microsleeps to hallucinations to increased risks of potentially fatal issues such as heart attacks and strokes, a lack of sleep can cause severe bodily harm. For some people, just missing a few hours of sleep can cause a slew of problems, from a higher risk of diabetes and obesity to depression and drowsy driving.

It’s definitely important to get at least seven to eight hours for adults, eight to 10 hours for teenagers, or seven hours for the elderly, according to the CDC. It’s so important for your overall health to get good and consistent sleep, not only because of the potential dangers but also because those who have better sleep typically experience more positive reactions, faster learning and behavioral function (4), and better emotional health, as well as better health in general.

If you need help getting a better night’s sleep, consider looking into a new mattress. We have dozens of mattress reviews that can help you make a purchase that will lead to more shuteye. Best of luck, and please remember: Guinness no longer recognizes sleepless stunts for their records due to the health risks, so we should take sleeplessness seriously, too!


  1. Williamson, A. and Fever, A. “Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication.” Occupational and Environmental Medicine. 2000 Oct; 57(10): 649–655.
  2. Mullington, J.M. et al. “Sleep Loss and Inflammation.” Best Practice & Research: Clinical Endocrinology & Metabolism. 2010 Oct; 24(5): 775-784.
  3. Besedovsky, L. “Sleep and immune function.” Pflügers Archiv: European Journal of Physiology. 2012 Jan; 463(1): 121–137.
  4. Wagner, U. et al. “Sleep inspires insight.” Nature. 2004 Jan; 427: 352-355.
The following two tabs change content below.

Joe Auer

Joe Auer is the editor of Mattress Clarity. He mainly focuses on mattress reviews and oversees the content across the site.

He likes things simple and take a straightforward, objective approach to his reviews. Joe has personally tested nearly 250 mattresses and always recommends people do their research before buying a new bed. He has been testing mattresses for over 5 years now, so he knows a thing or two when it comes to mattress selection. He has been cited as an authority in the industry by a number of large publications.

Joe has an undergraduate degree from Wake Forest University and an MBA from Columbia University.

2 thoughts on “What Would Happen If You Didn’t Sleep?”

Leave a Comment