[foobarbazqux]

If you don't sleep for long enough (about 7 days), you'll start to have visual and auditory hallucinations and also delusional thinking. You'll also experience severely reduced effectiveness of just about every system in your body. You might not die if you don't sleep for a year (say), but you'll probably get permanent brain damage.

[meowface]

Many people experience hallucinations if they stay awake for periods longer than 48 or even 36 hours.

[coolnow]

I think i believe this. A friend of mine is a virgin to late nights and all nighters. We were studying one night trying to cram for a test and communicating every so often on WhatsApp. At around 12AM, he told me he thought he was hallucinating. I laughed as he was only up for like 14 hours. He fell asleep shortly thereafter.

[meowface]

I can relate. I've only had two "all nighters" in my life, and felt utterly miserable each time.

Towards the end of both, I would develop minor visual hallucinations (seeing little things in the corner of my eye, etc.). 14 hours is a bit silly, though. 24 hours is probably the minimum for most people.

[sillysaurus2]

The point of science is to never fall back on claims like "you'll probably get permanent brain damage" unless it's known what brain damage you may get, along with bounds on a confidence interval. Otherwise we're just philosophizing.

[mattdmrs]

Science is slowly getting to those conclusions:

> Taken together, these changes in brain and body are further evidence that sleep deprivation is a chronic stressor and that the resulting allostatic load can contribute to cognitive problems, which can, in turn, further exacerbate pathways that lead to disease.

http://www.sciencedirect.com/science/article/pii/S0026049506...

[foobarbazqux]

Well, it's a testable hypothesis. We will probably never test it in humans or higher mammals due to ethical concerns.

[VladRussian2]

may be we willn't as we already did. Google "sleep deprivation experiment".

[aestra]

In clinical settings people experienced hallucinations with less than 48 hours of sleep deprivation.

http://www.amsciepub.com/doi/abs/10.2466/pms.1989.68.3.787?j...

I have no idea where you get 7 days from, I'm not sure its possible to stay awake for 7 days.

[foobarbazqux]

On reflection, maybe I got confused with the number of days you can go without water (also 7, at least according to my memory). I stayed awake for 5 days once and there was only a bare minimum of hallucination at the end. I could have stayed awake longer, it wasn't really hard by that point. The people I've known who stayed up forever on crystal meth typically started hallucinating after a week. I'm surprised that the limit is so much shorter, but I'll believe it, thanks for the link.