Nosebleeds in 11-month-old babies may be related to trauma, deviated septum, and nutritional deficiencies. 1. Trauma: when there is more dust and pollen in the air. It will make the baby feel that the nasal cavity is itchy, and it will be easy to pick the nostrils, leading to the rupture of the nasal mucosa blood vessels, causing nosebleeds. 2. Nasal septum deviation: commonly found in the convex side of the deviation, where the mucosa is thin, stimulated by the airflow and dust is easy to erosion and nosebleed. 3. Nutritional deficiencies: such as vitamin C, P, K or Ca deficiency, easy to increase the permeability and fragility of capillaries. At the same time, vitamin K is involved in the formation of plasminogen, Ca is also involved in blood clotting. Therefore, deficiency of the above substances easily leads to nosebleeds. Nosebleeds in 11-month-old babies may also be caused by other reasons. It is recommended to consult a doctor in time, undergo relevant examinations according to the doctor’s instructions, and identify the causes with the help of the doctor for targeted treatment or management.