There are many causes of nose bleeding in children, such as systemic diseases, trauma, environmental factors, etc., as follows: 1. Systemic diseases: for example, abnormal platelet function, coagulation disorders and other diseases can lead to nasal bleeding in children. However, nasal bleeding caused by this condition is usually accompanied by other symptoms, such as soft tissue, weight-bearing joint bleeding, as well as limited joint activity, deformity and so on. 2. Trauma: When the child’s nose is hit or the child often picks his nose, resulting in damage to the nasal mucosa, it is also easy to cause nasal bleeding. 3. Environmental factors: if the patient is in a dry environment for a long time or in an air-conditioned room for a long time, due to the low moisture content in the air, the nasal mucosa will rupture and bleed due to the dryness of the nasal mucosa. Children’s nose bleeding may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.