If nosebleeds occur frequently in the nostrils, for children, the most common cause of this condition is a vitamin deficiency due to nutritional imbalance caused by picky eating. You can take oral vitamin medications such as Sun Cun, and pay attention to whether the nasal mucosa is dry. For adults, dry nasal mucosa is more likely to cause nosebleeds. For treatment, you can use compound menthol nasal drops to drip the nose, and you can use physiological sea saline to do nasal rinse treatment. If the nosebleeds are frequent and unilateral, consider nasal septal deviation or bleeding due to swelling in the nasal cavity, such as hemangioma, papilloma, etc. If the bleeding is caused by a deviated septum or a nasal mass, most of the cases need to be considered for surgical treatment. However, if a swelling in the nasal cavity cannot be clearly diagnosed, pathological examination is required to clarify the diagnosis if necessary. Rarely, blood tests such as routine blood tests, coagulation tests and, if necessary, bone marrow aspiration tests are needed for hematologic diseases.