The causes of frequent nosebleeds in children may be related to allergy, trauma, environmental factors, personal habits and other diseases. 1. Allergy: especially in winter, nosebleeds are often induced by the fragility of the nasal mucosa and the dryness of the winter air. Most children with nosebleeds suffer from allergic rhinitis, in which the mucous membrane of the nasal cavity is often ulcerated. Children often rub their noses due to itching, and the nasal mucosa is injured, which leads to bleeding. 2. trauma: due to children’s activity is more vigorous, in the running and jumping during the time to suffer from heavy impact when the brittle suffered heavy impact, the fragile nose bleeding, in addition to play, if the foreign body into the nasal cavity, is also easy to cause nosebleed situation. 3. Environmental factors: in the change of season, or children in the air-conditioned room for a long time, the moisture content in the air is relatively small, the nasal mucosa is dry, easy to rupture the bleeding situation. 4. Personal habits: children often nosebleeds may also be caused by personal habits, if often digging nostrils, strenuous exercise, will lead to the child nasal mucosa erosion, nosebleeds. 5. Other diseases: some systemic diseases such as abnormal coagulation factors or tumors in the nasal cavity may also manifest as nosebleeds in the early stage. If children often have nosebleeds without any reason, it may be a harbinger of certain diseases, and they should consult a doctor in time to improve the relevant examinations. In addition, children with leukemia, hemophilia and other blood diseases are also prone to nosebleeds. If a child has frequent nosebleeds, it is recommended that he or she be closely monitored, and that he or she seek medical attention for any abnormalities, and that he or she be treated according to the doctor’s instructions.