F#432

Sleep deprivation is the condition of not having enough sleep; it can be either chronic or acute. A chronic sleep-restricted state can cause fatigue, daytime sleepiness, clumsiness and weight loss or weight gain.^[1] It adversely affects the brain and cognitive function.^[2]Few studies have compared the effects of acute total sleep deprivation and chronic partial sleep restriction.^[2] Complete absence of sleep over long periods is impossible for humans to achieve (unless they suffer from fatal familial insomnia); brief microsleeps cannot be avoided.^[3] Long-term total sleep deprivation has caused death in lab animals.^[4]