I thought this question to myself after I had to stay up for 36 hours recently. I was not really forced into it nor was I just trying to experiment and play with my mind or anything but I just wanted to catch up on doing things that I needed to do. Seems like there is not enough time in a day! Anyhow, after being up for 24 hours I started to feel really tired but I could keep going without any problem. Then the 30 hour mark came and life started to seem like it was getting in slower motion and I got kind of grumpy, things could anger me really quick. A little before I did go to sleep, around the 35 hour mark I actually seemed to be hallucinating kind of. I would see things out of the corner of my eyes and things like that. So I was just wondering, what is the longest you have stood awake? How did you feel? Tell me about it. I've heard stories from a few friends of mine that they have stood up for 4 or 5 days straight before but I find this very hard to believe, I'm not saying they are not telling the truth but I just wonder, how could they do that if I felt so crappy and almost dead after only 1 day and a half. I guess maybe in certain circumstances like a death in the family or something really life changing could keep you up for a long time than a situation like mine, just trying to catch up on things; but 5 days? I don't know. So let me know the longest you have stood up.