why does my nose bleed when i'm sleepin?

Answer 1

Mine used to do that when I was younger. It can be caused by dry air or allergies. My sinuses would get so swollen and clogged the pressure would make my nose bleed. If you are having allergies, you need a good allergy medicine.

Answer 2

Dry air and allergies are two causes. Dried mucous can press on and open fragile capallaries in your nose. You may also be rubbing or picking your nose in your sleep!
Try gently applying a little vaseline inside your nose before bedtime.