Eli5 why can’t we continuously take caffeine and never sleep?

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I work overnight shifts (11pm-7am) and take caffeine pills to stay awake. When I get home, even if I take more caffeine I’m sometimes still too tired and fall asleep. Why does it eventually stop working? Is there some sort of chemical limit? Why can’t caffeine replace sleep for longer periods of time (like days on end)?

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Anonymous 0 Comments

When you are awake, your brain produces various waste chemical byproducts as part of its metabolism while performing the various functions needed to keep you aware, alert, and active. The longer you stay awake, the more of these waste products it produces, until they begin to interfere with the functioning of the brain. The mechanism the brain has to remove these waste products cannot operate while the brain is awake. Caffeine and other things can give a temporary rush that can help the brain work around the waste products to continue working, but eventually the waste products build up too far.

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