Having recently pulled an "all-nighter" while trying to fix a fatal bug in our release code, I started thinking of any health risks that I might have.

What are the adverse effects of staying up for staying up for 42 hours, considering I took no caffeine or other stimulants, as well as no depressants such as alcohol?

Upon googling I found a lack of facts, what would be good is a list of effects and rough times that they start happening. And any significant problems I would face, but moreover I would like to know what causes them? Unfortunately I only studied Biology until GCSE (UK - SAT/TAKS Alternative) and might need some simplified explanations or links to help understand more complex tasks.

I'm not even sure if this question is grammatically correct, and my brain power has slowly dwindled, should I be worried? I have read this and understand it to a vague extend.

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    $\begingroup$ Something that I know is that it affects memory negatively. If you search google scholar then you'll get a lot of articles on sleep deprivation experiments. $\endgroup$
    Aug 20, 2014 at 5:06
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    $\begingroup$ I've never heard of google scholar before. Thanks for pointing me in that direction! It seems a cool google sub-site. Also thanks for the information on more sleep deprivation experiments. $\endgroup$ Aug 20, 2014 at 5:36
  • $\begingroup$ Personally, I notice that most cognitive effects of sleep deprivation become very strong during times in which I would be habitually asleep, and minimal when I would awake normally. Arousal also seems to minimize perception of sleepiness, while being idle/bored makes it worse. You don't seem to have experienced this, your symptoms just get worse and worse. $\endgroup$
    – Superbest
    Aug 20, 2014 at 20:03
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    $\begingroup$ You seemed to have answered your own question with your edit. $\endgroup$ Aug 20, 2014 at 21:15
  • $\begingroup$ I noticed it worst when I was actually having a shower Superbest - Not sure if it was the heat that made be drowsy or what. I guess I did Eastman, however why this is caused was not answered, and whether there are any lasting effects. $\endgroup$ Aug 21, 2014 at 13:42

2 Answers 2


24 Hour Mark

The consequences of sleep deprivation at 24 hours is comparable to the cognitive impairment of someone with a blood-alcohol content of 0.10 percent, according to a 2010 study in the International Journal of Occupational Medicine and Environmental Health.

36 Hours

Now your health begins to be at risk. High levels of inflammatory markers are in the bloodstream, said Cralle, which can eventually lead to cardiovascular disease and high blood pressure. Additionally, hormones are affected — your emotions can be all over the place.

48 Hours

After two days of no sleep, the body begins compensating by shutting down for microsleeps, episodes that last from half a second to half a minute and are usually followed by a period of disorientation. “The person experiencing a microsleep falls asleep regardless of the activity they are engaged in,” she said. Microsleeps are similar to blackouts, and a person experiencing them is not consciously aware that they're occurring.

72 Hours

Expect significant deficits in concentration, motivation, perception, and other higher mental processes after many sleepless hours, Cralle said. “Even simple conversations can be a chore,” noted Kelley. This is when the mind is ripe for hallucinations. Kelley recalled a time he was on guard duty and repeatedly saw someone standing with a rifle in the woods, ready to sneak into camp. Upon closer inspection, he determined he was actually looking at a branch and shadows.

Sleep: Why We Need It and What Happens Without It - SciShow from Humza Zaidi's comment



According to healthysleep.med.harvard.edu:

Sleep and Disease Risk The price of insufficient sleep may be poor health. Study after study has revealed that people who sleep poorly are at greater risk for a number of diseases and health problems. And now the search is on to discover why this might be. more

Sleep, Performance, and Public Safety Lack of sleep exacts a toll on perception and judgment. In the workplace, its effects can be seen in reduced efficiency and productivity, errors, and accidents. Sometimes the effects can even be deadly, as in the case of drowsy driving fatalities. more

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    $\begingroup$ Little more specific citation/reference will be better. $\endgroup$
    – Dexter
    Aug 7, 2017 at 17:25
  • $\begingroup$ Edited :) @Dexter $\endgroup$
    – liam
    Aug 7, 2017 at 17:46

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