Eli5: Why do we need to sleep so much, what happens in the body when asleep that cannot happen while normal resting or relaxing? Or is it just for the brain?

Question

Eli5: Why do we need to sleep so much, what happens in the body when asleep that cannot happen while normal resting or relaxing? Or is it just for the brain?

In: Biology

Answer 1

We simply do not know. We do know what happens when you don’t sleep though. Moodiness, fatigue, weaker willpower, lack of concentration, hallucinations and even death. Thus most hypothesises are based on what gets affected when you don’t sleep.