Question: How do you get nightmares?

Jess Wade answered on 23 Jun 2015:

When we go to sleep our brains process all of the experiences we’ve had that day and sort out what we should and shouldn’t store in our memory- it’s like a great hard drive on a computer! We switch off some parts of our brains, and our metabolism slows down. That means we don’t need to pump so much blood around our body or eat food to stay alive. When we’re busy processing our memories, we go over all the thoughts we’ve had that day. BEcause there are no other distractions, sometimes these can turn into bad dreams as we try to understand what has happened. There are different stages of sleep, and scientists think nightmares happen during rapid eye movement sleep.