Children always consider nosebleeds may be behavioral habits, blood clotting dysfunction, rhinitis and other reasons. 1. Behavioral habits: it may be that children usually nose uncomfortable, habitual hand digging nostrils, picking broken capillaries, thus the phenomenon of nosebleeds. 2. Coagulation dysfunction: it refers to the blood coagulation disorder caused by various reasons, which is mainly manifested as nosebleed, bleeding gums and other symptoms, and may be accompanied by dizziness, fatigue, lack of concentration and other symptoms. 3. Rhinitis: due to the local inflammatory stimulation of the nasal cavity, common allergic rhinitis, sinusitis, etc., leading to the local mucous membrane of the nasal cavity to appear erosion, nasal erosion after the symptoms of nosebleed. Children always nosebleed may also have other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.