Children’s nosebleeds and formaldehyde may be related, long-term exposure to formaldehyde can lead to direct stimulation or trigger blood system disorders, leading to nosebleeds; in addition to this, nosebleeds are also related to other diseases and so on. Formaldehyde is a volatile irritant gas, if long-term exposure to this chemical may lead to nosebleeds due to its direct stimulation of the nasal mucosa; it may also induce hematologic disorders, such as leukemia, aplastic anemia, etc., which may involve the nasal cavity and lead to nosebleeds. The occurrence of nosebleeds may also be related to a variety of other causes, including nasal diseases, such as sinusitis, deviated septum, nasal trauma, nasal foreign bodies or occupations, etc.; other systemic diseases, such as hemophilia, immune thrombocytopenia, etc.; and medication factors, such as the use of anticoagulant drugs such as warfarin. It is recommended that people with recurrent nosebleeds or severe symptoms of nosebleeds should consult a doctor in a timely manner, have relevant examinations to clarify the specific causes of nosebleeds, and take active treatment.