Why do we have nightmares?

Ahhh! There is nothing worse than waking up in the middle of the night after a nightmare.  Your heart is pounding, you’re all sweaty and suddenly your room seems so dark. Sometimes, you’re almost too scared to close your eyes and try to fall back asleep.  What’s the point of these scary dreams anyway? Is there a reason we have them at all?  We reached out to sleep scientist Ketema Paul to get the answer.  Got a question keeping you up at night?  Send it to us at brains on dot org slash contact and we’ll wake you up with the answer.