eli5: How does lack of sleep kill someone?
In: Biology
Imagine your brain as constantly generating trash, and sleep takes out the trash. If you don’t sleep, your brain will drown itself in trash. That’s the ELI5 version.
Lack of sleep causes sleep deprivation, which mainly results in slower reaction time and, you know, difficulty of staying awake.
I believe, lack of sleep generally kills people in indirect ways, like if a person falls asleep behind a car wheel or while operating heavy machinery.
Your body does important things when it sleeps. If those things don’t get done, it thinks you’re sick, so it sends signals to you to tell you to sleep. Those signals impact your focus, memory, hormones, and even cause you to fall asleep at times when you need to be alert for your safety. It won’t directly kill you, but the conditions it causes can, either quickly–like dozing off while driving–or slowly–like by sending messages to your body to eat and rest, when in fact you don’t need to eat so you gain unhealthy weight quickly.
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I suffered for 5 to 7 years from secondary Hypersomnia due to undiagnosed Obstructive Sleep Apnea. Put simply, I didn’t get a good, complete night’s rest for half a decade or more. And it was the hypersomnia that finally got me to a doctor. After a sleep study, it was determined I’d “wake up” more than 25 times per hour due to my airways being blocked.
My sex drive was broken and I’d gained 40 pounds in three years due to hormone imbalances that impacted metabolism, I was forgetting important things, and I would feel drowsy and doze off when doing important tasks, including driving.
There’s actually an extremely rare prion disease known as Fatal Familial Insomnia. It literally takes away the brains ability to go to sleep. So much so that not even a medically induced coma was able to get a patient into a state of true sleep. According to Wikipedia, as the insomnia worsens for people with FFI, they begin to have paranoia, panic attacks and hallucinate. Once they reach the stage of the disease where sleep becomes impossible they lose weight and they mentally deteriorate rapidly. The final stage of the disease, which arrives after a couple of months of no sleep, is marked by dementia and the person tends to become mute or completely non-responsive. Death follows shortly thereafter.
Here’s some bonus related info on the importance of sleep.
Most people know that horses can sleep standing up, but actually to get the few minutes of REM sleep a horse needs everyday, it has to lay down. As horses age and become unable to get up, they quit laying down to sleep and REM sleep deprivation accelerates their declining health.
It is not fully understood, and it’s probably overly simplifying to say lack of sleep kills the horse, but it is a contributing factor. REM sleep deprived horses may suddenly collapse and injure themselves as they fall. They demonstrate what we think is confusion and may forget to eat and drink properly, and a horses digestive system requires a near constant flow of roughage to prevent gastrointestinal injury.
Fruit fly study reveals gut’s role in causing death by sleep deprivation
https://news.harvard.edu/gazette/story/2020/06/study-reveals-guts-role-in-causing-death-by-sleep-deprivation/
It is hard to tell because fatal familial insomnia is EXTREMELY rare, but the lack of sleep probably technically doesn’t kill you.
You will die of something else that your body just can’t fight off or recover from.
It’s kind of like Disneyland: although you see some employees sweeping up during the day, all the deep cleaning and repairs can only happen when the park is shut down at night. If you don’t have that night shift to tidy things up, then the “unemptied trash” and “broken stuff” will build up pretty fast during the day and will overwhelm the park/body while business tries to run as usual.
You’re driving in your car, coming home from work, but you had been working until 3AM every day. You close your eyes for a second and before you can open them again, you’ve drifted into the oncoming lane of traffic and you’ve just hit a minivan with three kids in it.
My friend from high school, was doing a project at University and his team had won design competition. They then had to get to Montreal (from Toronto) for the next day, so they packed up their presentation and model, got in the car in the evening and never made it to Montreal… he fell asleep and hit another car head on on the Eastbound 401. They had all been staying up to work on this thing, on top of regular school work.
A lot of vague and wrong answers here, OP. The truth is that we don’t necessarily know that lack of sleep can kill a human. The longest anyone has officially been awake is around 11 days, although unofficial attempts have been reported that go on a bit longer (Guinness World Records stopped recording attempts to deter people). None of those people died, and all made full recoveries as far as recorded data knows.
Note that we’re not talking here about Fatal Familial Insomnia, the prion disease that someone else mentioned. That’s a degenerative disease which literally turns your brain into a sponge-like structure. Like most degenerative disorders, the likely cause of death with FFI in the end is failure of autonomic function like breathing and swallowing. It’s debated, but lack of sleep is generally not considered the fatal aspect. In any case, it’s a different thing from lack of sleep.
The evidence that acute deprivation can cause death comes from animals – this has been demonstrated in a few species, most notably rats. These studies suggest stress-related problems including reduced immune function and cardiovascular stress which may lead to death. The suggestions that others have put forward (e.g., brain waste removal) have either not been supported or not been investigated in such studies. However, evidence from animals is also mixed to some extent – for example when some flies are genetically altered to not sleep, they do not die from the sleep deprivation.
Does this mean that sleep is not important? Absolutely not. We know that chronic sleep deprivation (even just getting less than ideal amounts each night) can cause cognitive problems and is a risk factor for various disorders from depression to dementia. We don’t know the explicit function of sleep (we see various processes such as waste removal, memory consolidation, etc. which are optimised during sleep but not necessarily dependant on it), but we know it’s likely evolved as a specialised and functional stage of our being. We also see it in some form in every known species, which again highlights its importance. That does not mean we have concrete evidence for acute sleep deprivation being lethal, though.
TLDR: sleep deprivation won’t necessarily kill you. We don’t have good evidence in humans showing it will. Sleep is very important for health but lack of it might not explicitly kill you.
edit to be more explicit: no one reading this will die of sleep deprivation. never been recorded, ever. sleep well folks
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