Common causes of nosebleeds in children There are many causes of nosebleeds in children. The following are common causes: 1. Dry weather in the nasal cavity or being in an air-conditioned room for a long time will cause the mucous membrane in the child\’s nasal cavity to lose moisture and become Fragile. At this time, when a child blows his nose hard or picks his nose, it is easy to puncture the blood vessels in the nasal cavity and cause nosebleeds. 2. Children with trauma accidentally bump their nose or fall while playing, practicing sports, studying and other activities, which can also cause the blood vessels in the nasal cavity to rupture.