The causes of nosebleeds in children may be related to nasal foreign bodies, nasal injury or nasal inflammation. 1. Nasal foreign body: most of the unilateral nosebleeds, may be due to the nature of small children playful, will be toys or small stones placed in the nasal cavity, the nasal mucosa friction, and then cause the nasal mucosa erosion bleeding. 2. Nasal injury: including the cause of nosebleeds in small children, may be due to poor nose picking habits, such as when picking the nose with the fingernail, may cause nasal mucosal erosion, and then there will be symptoms of nosebleeds. 3. Nasal inflammation: small children with sinusitis, acute and chronic rhinitis and other diseases, may be in the inflammation of the invasion, resulting in the mucous membrane of the nasal cavity becomes brittle, it is easy to cause capillary rupture bleeding. Children with nosebleeds may also have other causes, so if necessary, you can cooperate with the doctor to do further examination, a clear diagnosis and then do the treatment.