The longest time a human being has gone without sleep is 11 days and 25 minutes. The world record was set by American 17-year-old Randy Gardner in 1963. Others including Finland’s Toimi Soini and the UK’s Maureen Weston and Tony Wright have since claimed to have beaten this time, but none of them were studied as closely as Gardner. Without close monitoring it is difficult to verify these claims.
The effects of sleep deprivation are well documented, with symptoms including irritability, taking longer to make decisions, and cognitive rigidity, in which individuals can only think about things in one fixed way. Other side effects include loss of motivation, higher blood pressure, paranoia, memory issues, mood changes, visual problems, hallucinations and difficulties with speech.
Gardner’s record was observed by William Dement, who noted that Gardner experienced many of these side-effects, including an impairment of his cognitive and sensory abilities. He didn’t consume any stimulant drugs to keep himself awake, but did have people around him to distract him from falling asleep.