Nosebleeds in children who fall asleep at night may be due to physiologic factors or pathological conditions. Physiological conditions such as environmental reasons, pathological conditions may be due to thrombocytopenia, chronic rhinitis and so on. 1. environmental factors: for example, the air is too dry, etc., the child’s nasal mucosa is fragile, sensitive to the environment, which can lead to children fall asleep at night nosebleed. 2. Thrombocytopenia: many kinds of diseases such as immune thrombocytopenia, hypersplenism, bone marrow disease, etc., so that the number of platelets in the body is reduced, nosebleeds can occur. 3. If the child suffers from chronic rhinitis, there may be a lot of snot or nose blockage, and the child’s self-control is generally not high, in this case, they may use their hands to pick the nasal cavity, the nasal mucosa or capillaries will be damaged, which led to the phenomenon of nosebleeds. Remind everyone is when the child fell asleep at night nosebleed long-term difficult to relieve, should go to the hospital in a timely manner, in accordance with the doctor’s instructions for symptomatic treatment.