Question: Why do we have to sleep? Is it just because our body needs to re energise

Alison Whitaker answered on 18 Jun 2015:

I don’t think anyone knows the full reasons behind why we sleep. Certainly sleep allows us to process and re-energise physically and mentally. Studies have looked at what happens when we don’t sleep to better understand what the effects of sleeping are. Mental processing becomes reduced and you have a lack of energy. I suspect there is more to it, but I don’t know for sure!