You can last longer without food than you can go without sleep. Missing one night’s sleep makes you crabby and clumsy, but two sleepless nights drain your brainpower.
You have trouble thinking and doing things. Five nights awake, and you hallucinate, or see things that aren’t there. Death may be next, because your brain can’t maintain vital body functions without sleep. The official no-sleep record? In 1968, Bertha van der Merwe of South Africa went without sleep for 11 days, 18 hours, and 55 minutes, watched by doctors in a hospital.
Sleep is a vacation for your body, but not for your brain, which works as hard at night as it does all day. Scientists aren’t sure exactly what the brain does at night. Is it replacing used-up chemicals, organizing and disposing of information, solving problems, or doing other tasks? Whatever the brain’s nightly tasks may be, it has to do them to keep you alive and functioning.