How long can the human body go without sleep?

Well...: Studies have been done with people apparently awake 8-10 days but there is evidence of micro-sleeping where there are transient periods of reduced responsiveness and consciousness during that time. The record is apparently 11 days. It is not good for mental and physical health so not recommended to try

Two weeks: People tend to need about seven hours of sleep per 24 hours; some need a bit more, or less. Long-term sleep of less than six hours per day can have harmful effects. Significant adverse physiologic effects can be seen as soon as 24 hours without sleep. Sleep loss is also associated with motor-vehicle accidents. Death can be expected to occur within approximately 14-28 days without sleep.

Some studies: Suggest up to 11 days but it is unlikely that could happen in the absence of experimental lab. People after 2 to 3 days of complete of sleep deprivation will fall asleep even while talking