Nosebleeds in young people can be caused by nasal mucous membrane damage, environmental factors, systemic factors and nasal diseases. 1. Traumatic factors: digging one’s nose and blowing one’s nose may cause trauma to the nasal mucosa due to mechanical impact, which may lead to nosebleeds. 2. Environmental factors: young people’s activities are larger, the nasal breathing flow is faster, in the weather is too hot or live in a dry environment, can easily lead to nasal mucosa dry, will increase the risk of nasal blood vessel rupture, bleeding. 3. Systemic diseases: some young people with unstable systemic immune system function, such as leukemia, hemophilia, hemorrhagic fever and other diseases, may lead to symptoms of nosebleed. 4. Nasal diseases: dry rhinitis, acute rhinitis, nasal tumor, nasal septal ulcer, atrophic rhinitis may lead to damage of nasal mucosa and trigger nosebleed. The causes of nosebleeds in young people are complex and varied, so it is recommended to actively go to the hospital for examination and standardized treatment after a clear diagnosis under the guidance of the doctor.