Longest time without longer term affects/ damage?

How long can some one safely go without sleeping? To the point where OTHER then being really tired or that kind of expected thing starts to happen.Longest time without longer term affects/ damage?
Anything longer then 24 hours will start you feeling loopy. I beleive the record for staying awake is 11 days, but that guy was insane by the time he hit that mark. Lack of sleep can kill you so be careful. Not sleeping gives you the same feeling as being drunk, so be careful with any activity like driving or drinking any alcohol which can add to the effect.
Safely, probably no more than a day. Your judgement, coordination, and thinking cap all start going out the window by then.
48 hours was my limit after that normal things became very hard to do, even walking was a chore. You can also be so tired that you can't even fall asleep I have experienced that too, not fun. I am a City snow plow truck driver and I plow roads during snow storms we are not allowed to sleep if the roads aren't cleared.
I asked this question not long before you did! I found an interesting article published on the website of Stanford University about research done on students who had about four hours of sleep each day at different times, and found that one group had better "wakefulness tests" results than the other. You should check it out.