I have a 6 year old son and his nose bleeds at night.it happens often and it is in any weather anytime. should i be worried?

Common issue: It is common for kids to wake to a bloody pillow. This comes from the frail capillaries in his nose that break when he rubs his face(nose) into the pillow when half asleep. It is a sign of irritant itching/allergies. Placing nose drops or saline gel (NASAL or OCEAN) in the nose at bedtime usually reduces the frequency. Eliminating dust/ perfumes from his environment also helps.