Sleep is something we all need, and something we’ve all complained about not getting enough of. We struggle the day after pulling an all nighter, but how long can we actually survive without sleeping?

No one actually knows. What we do know is that the longest time anyone has ever stayed awake for is 11 days, 264 hours to be precise, a record set by Randy Gardner, who was a high school student when he attempted it.

How much sleep should we be getting?

The amount of sleep everyone needs differs from person to person depending on health and age. Babies for example spend the majority of their days asleep, hence why they keep their parents up all night! But then from around school age to old age, we need between 7 and 10 hours – so you can see why it’s not the best idea to stay up till the early hours of the morning on a school night.

How long can we go without sleep

Why do we need to sleep? And why so much?

We need sleep to process our thoughts, to go over what’s happened in the day and sort memories like a computer would into files. Short term memories become long term memories. This is what gives us clarity, and space to take in new information when a new day dawns.

We sleep for so many hours so that our body can restore itself by repairing any damage and growing our muscles whilst we’re not using them. Got any cuts or scrapes? They’re going to take a lot longer to heal if you don’t get enough sleep. We also need sleep for survival, it’s not just a luxury, it’s a necessity.

What happens when we go without sleep?

Aside from being incredibly tired, depriving yourself of sleep has other consequences.

It’s kind of a given that you’re going to be a lot less alert if you haven’t slept for a while, there’ll be a haze of exhaustion. You don’t even have to have missed a lot of sleep for this to kick in though, it might start to affect you if it was just a particularly rough night.

We all have those moments when we just cant function, those times we desperately tell our minds to focus but just can’t see through the tired haze. You can imagine how much worse it gets the longer you force yourself to stay awake. It’s safe to say you’d have to rule out doing anything that requires any attention.

Your vision can also start to be affected as a result of lack of alertness, vision might become blurry, a bit like being drunk you might say! Just as you cant focus on the now, you start to forget things as well. You may not remember that conversation you had only five minutes ago, or you may forget the one important thing you were supposed to do today. Lack of sleep impairs your memory.

If you’re mind hasn’t had the time to sort through your memories, as it usually does when you sleep, then it’s a lot more difficult to take in new memories, there’s simply not enough space.

You’ll need a hell of a lot more food to make up for the energy you’re using to stay awake. For a lot of people this links to weight gain, a side effect that would put anyone off staying awake for too long!

The longer you leave it without sleeping the worse your side effects will be. A couple of days or more without sleep could see you struggling to form simple sentences, and even hallucinating.

There are more severe consequences as well, to do with your long term health. Your heart will struggle under the strain of exhaustion, your metabolism will slow down and you’ll be at higher risk of high blood pressure and developing cardiovascular disease. Not something any of us want.

Though there haven’t been any cases of death definitely caused directly by lack of sleep in humans, in animals long term sleep deprivation has lead to their demise. Those with fatal familial insomnia, which I’ll move onto in a moment, have died but it’s unsure whether this is a direct result of sleep deprivation.

Considering these side effects can begin after just one sleepless night, the risks are definitely enough to put you off trying it for longer. The thrill of staying awake suddenly seems a lot less impressive!

Is it possible to FORCE yourself to stay awake?

Obviously for a night or two we can push ourselves to stay awake for whatever reason, maybe theres a couple of wild nights in a row, or maybe you’ve got a deadline coming up and just cant afford to waste time in bed. But any more than that and it becomes incredibly difficult.

Your mind will actually start to just shut down, and that’s when you’ll find yourself falling asleep involuntarily, like toddlers when they fall asleep with their face in their dinners. It takes a lot to fight your body when it knows what it needs.

So it is possible to force yourself to stay up, as Randy Gardner did for 11 days, but remember that that’s a world record. It’s not easy and anything more than a couple of days  will have harmful effects.

Fatal familial insomnia (FFI)

Fatal familial insomnia is an exception to the normal amount of time we can go without sleep. It is neurological disease that means you literally can’t sleep. It’s caused by a mutation of a protein and can develop spontaneously. You’ll be pleased to hear though that it is incredibly rare, with only around 100 people in the world suffering from it.

FFI is the one case where it is possible to stay awake, but it’s not a choice. Those diagnosed are completely unable to sleep, regardless of how tired they are, and it’s not pleasant.

There are four stages:

Increasing insomnia – this stage lasts for 4 months.

Panic attacks, paranoia, hallucinations – all continue for around 5 months.

Unable to sleep at all – this goes on for around 3 months and causes extreme weight loss.

Dementia, and loss of voice and responsiveness – this happens over 6 months.

After these stages, unfortunately death ensues. Life expectancy from the onset of the disease is 18 months.

Summary

For the majority though, the answer to how long we can go without sleep is not very long. More than a couple of days and the effects can become quite severe. We wouldn’t want to stay awake though, doing an all nighter is one thing, but depriving yourself of multiple nights of rest just isn’t something anyone would want to do, and not something you’d be able to do without a lot of difficulty either.

Our bodies know what we need, if we feel tired, usually we have the sense to go to bed, no matter how many things tempt us to stay awake.