There are no documented cases of a healthy human dying from total sleep deprivation (excluding accidents), aside from those suffering from Fatal Familial Insomnia. In carefully monitored experiments, several normal research subjects stayed awake for 10 days. While they all experienced cognitive deficits in memory, concentration, etc, none of them experienced serious medical, neurological, physiological or psychiatric problems [1]. Total sleep deprivation in rats leads to death in around 28 days. Death occurs later if only REM sleep is eliminated. In humans, extended sleep deprivation causes microsleep sessions to develop. A person who has fatal familial insomnia may die after several months with no sleep at all; people without this condition may experience dementia or develop permanent personality changes within the first few weeks.

Death is not the factor that needs to be first worried about when considering sleep deprivation. What one needs to worry about most are the psychological effects of sleep deprivation. After about 5-6 days without REM sleep, the body experiences a phenomenon in which the body sleeps while the mind is awake, which is what causes hallucinations and personality changes that can last throughout the rest of ones life.

No one has ever managed to stay awake for much longer than about 10 days. Any longer and they keel over, strongly suggesting that a good kip brings real biological benefit. We simply cannot do without sleep. It is not just an evolutionary knockout drop. On the other hand, these experiments indicate it is possible to stay awake long enough at least to watch a Test match. The record for sleeplessness - held by 17-year-old American Randy Gardner - is 11 days, a feat achieved only by taking lots of cold showers, going for runs and playing games such as pinball. It is only after several days that problems start for people in such experiments: panics, delusions, voices, hideous mental images, memories of Steve Harmison's bowling, that sort of thing.

ok, the max you can stay up is i think 11 days, after that your brain starts shutting down its functions because of the lack of sleep, and yes, it can cause brain damage and parts of the brain may even just shut down