What Happens If You Stay Awake Too Long?

Well, what happens to us when we stay awake for too long? There's not very much information out there, but here you'll find a timeline of the events that occur both mentally and physically when we don't sleep.

After an 8 hour sleep, staying awake for:
2 hours: Our brains are well into focus, we are feeling refreshed, energised and usually perform at our peak level.
4 hours: We may start to yawn, but this is usually just a natural human evolved occurence that tells us we are still awake. Why we need a reminder like that, I don't know.
8 hours: We start to simply feel a little more relaxed, and may start to feel like napping or just taking a short break from whatever it is we are doing.
11 hours: Our brains go into recollection mode, where it sorts out all the things we've taken in over the course of the day (or night). This sudden extra working of the brain causes our muscles to become more limp, making us want to lie down and rest, if not have a short sleep.
14 hours: Our brains are telling us to turn the lights out. We may yawn a lot, begin to develop headaches and our eyes may become red, itchy and feel heavy. This is all due to our brain trying to sort out the day's events for our memories, which is best done while we sleep. (this is explained further below.)
16 hours: We start to feel light-headed and may have trouble keeping our eyes open. We find our arms to be heavy to lift by themselves and the headaches begin to get more and more intense.
20 hours: 20 hours awake is when our body starts going into protection mode. Our brain can't properly sort and staple all the day's events because it is too busy powering our alertness, reactions, and various other things like what we say, what we do and mechanical processes like blinking and breathing consciously. This causes the headaches to worsen as a way of our brain telling us to get to sleep as soon as possible.
26 hours: Anything over and above 26 hours without sleep is simply quite dangerous for you. You may begin to lose your co-ordination and find it hard to keep your balance, you develop short-term memory loss and have trouble recalling things you recently did and said, and you may start to hallucinate. When this starts happening, that is the signal to sleep straight away.
30 hours: At 30 hours we begin to lose our sense of smell and touch. This is because the receptors in our hands and noses aren't functioning properly due to the lack of rest we have recieved. Your brain is still trying to do a million things at once, so partially losing sight or your sense of hearing after 30 hours awake is not uncommon.
40 hours: After 40 hours awake our body goes into fight or flight. It releases adrenaline as a way of not giving us a thrill, but to stay awake. Our body can no longer rely on the accumulated 'rest' it's recieved, as it hasn't recieved any for nearly two days straight. Hallucinations become more vivid and microsleeps (involuntary 5-10 mins of deep sleep) may occur.
48 hours: After 48 hours (2 full days of being awake) our brain starts to get deprived of its own energy. Not food or water energy, but mental energy to carry out its natural processes. This is why after 48 hours we may lose control of our arms, may not be able to walk at all, and may have involuntary spasms that could include all or parts of the body. Hallucinations become very lifelike at this point and we begin to slur our talking as our tongue loses energy and is not being powered by the brain anymore.
64 hours: 64 hours is when our body begins to shut down. We may totally lose control of our arms or legs, and begin to completely lose some or all of our senses. Vision becomes blurry without any lapse to normal sight, and we begin to lose our thought functions. This is when we see things and hear things that aren't happening, and can't comprehend or reply to someone speaking or performing an action to us. 64 hours awake is the 'danger zone'. You normally have about another 4 hours without sleep before lapsing into unconsciousness or involuntary deep sleep.
68 hours: Our body generally shuts off at this point, and lapses into unconsciousness or deep REM sleep against our will. This will NOT happen if we are kept awake. We usually recover from our lack of sleep during this unconsciousness or deep sleep.
68+ hours: If kept awake for more than 68 hours, our body is generally just completely worn out, useless, limp and unable to function. We may be able to very faintly see or hear something, but we are usually too tired to even open our mouths or move any part of our body.

There are no known long-term effects of staying awake. Some people have suggested brain damage may occur, however this has not happened in any experiments were people were subjected to long periods of time without sleep.

Q: What happens if you stay awake too long?
A: We know that long periods without sleep can cause problems with co-ordination, balance, sight, sound and comprehension. The longer you are awake, the worse the effects become, including hallucinations, microsleeps, loss of senses and total inability to perform any bodily functions voluntarily. You should only stay awake for a maximum of 14 hours at a time and should always get a solid 8 hour sleep when you go to bed.