Woke up with blood on my pillow. how did i get a bloody nose in my sleep?

Bloody nose: Here are some possible reasons. Do any of them apply? Nose bleed reasons: nasal congestion or nasal dryness, ^ blood pressure, excessive use of decongestants, being at ^ altitude, trauma to nose, nose picking, or blowing the nose hard. Bacterial & viral infections can ^ risk as well as bleeding disorders. Recurrent nose bleeds may be due to broken vessel in the nose.