Being chased or chased ppl?

Have you ever had these kind of dreams, being chased by people/ghost or you chased ppl? If you do, then you should know how tired it will be no matter you are being chased or there are someone chasing you.

It makes me wonder, how come we will have these dreams? Is it because in real life we always chase people? Or people always chasing us to finish our job and etc? Or is it because we are under a lot of stress/pressure?