How long can a person stay awake without ...

The record for the longest period without sleep is 18 days, 21 hours, 40 minutes during a rocking chair marathon. The record holder reported hallucinations, paranoia, blurred vision, slurred speech and memory and concentration lapses. The record holder, Peter Tripp was a broadcaster, and the last 66 hours were only accomplished with help of drugs administered by doctors. This was in 1959.

In 1964 another record was set, when randy Gardner (who was 17 at the time) went without sleep or any drugs for 264 hours (11 days). 

The Guinness Book of Record since then refused to take any more records, because it is not proved that this is not dangerous.

As someone who cares for his body i can tell you that 20 hours is more than enough, and 18 is better. 

Hi,
I wonder if there is an exact answer (simply because one can stand only 2 days and another can stand 3,4,5 or more).   However, I can share my own expirence.  For some reason I had to be awake and do a certain job.  It's a hell of an expirence......  After about 3 days you see illusions ..... (you really see people that are not there, and you hear voices, loud and clear, and nobody is there)..... a day latter you fall "half sleep" while you walk..... people in front of you are getting smaller as if they went far away from you..... Don't try it, it's bad. 
Best regards,

I don´t tell you the records by also how long I can be without sleep. It was more than 32 hours but I feel very bad...