The site of nasal bleeding in children is mostly in the first 1/3 of the nasal septum in the area of the capillary network, also called the Lai’s area. The vascular network in this area is superficial and distributed in the mucosal layer of the nasal septum. Generally, the capillary network in children is not well developed, and nosebleeds tend to occur when the nasal mucosa is dry, capillaries are dilated, or the nasal cavity is inflamed or irritated. The detailed causes of nosebleeds in children are as follows: 1, nasal inflammation or disease Various rhinitis, sinusitis, nasal tuberculosis, nasal syphilis, nasal trauma, deviated septum, nasal foreign body, nasal tumor, etc.; 2, poor climatic conditions Dry air, heat, high room temperature, or low air pressure, cold, etc. can cause nosebleeds; 3, the bad habit of picking nostrils Some children will pick their nostrils with their hands, and when the nasal mucosa is dry, it is easy to When the nasal mucosa is dry, it is easy to pick the nose and bleed; 4, picky eating Picky eating, partial eating, not eating green vegetables, can cause vitamin deficiency, resulting in nosebleeds; 5, systemic diseases Certain systemic diseases, such as fever, hypertension, arteriosclerosis, leukemia, thrombocytopenic purpura, aplastic anemia, etc., can also cause nosebleeds.