Children’s old nosebleed is not necessarily leukemia, there are many reasons, such as nasal septum curvature, rhinitis, nasal foreign body. 1. Deviated nasal septum: near the convex surface of deviated nasal septum or the ridge of nasal septum, the mucous membrane is thin, the flow direction of air current changes here, and the mucous membrane becomes dry, which can easily cause blood vessel rupture and bleeding. 2. Rhinitis: inflammatory stimulation of the nasal mucosa is fragile, easy to appear nasal mucosa erosion, ulceration and bleeding, often accompanied by runny, fever, headache and other symptoms. 3. Nasal foreign body: because of the nasal foreign body long-term retention in the nasal cavity, can lead to nasal mucosa erosion and bleeding. Children with old nosebleeds may have other causes such as idiopathic thrombocytopenic purpura, hemophilia, not necessarily leukemia, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, standardized treatment.