What are the reasons for nosebleeds without any reason?

Patient's question:

Here! Previous treatment history and effectiveness: None
Regardless of what kind of assistance: Want to consult a doctor about what might have caused this condition? Is there a possibility of getting leukemia?...

Doctor's answer:

Okay, here is the translation following your instructions:
It's good to confirm, you need to take the child to the hospital for a thorough check-up to see if it is.
However, in general, nosebleeds in children are often a sign of the flu or acute respiratory diseases.
If purulent secretions are flowing from the nose before the nosebleed, then a foreign body might be the main cause.
In this case, it can only be removed by a doctor.
Recommendations: Children are active and playful, and they often accidentally injure their noses, triggering nosebleeds.
Additionally, they may also stick foreign objects into their nostrils out of curiosity, causing the nasal mucosa to corrode.
These situations can happen anytime, and the amount of blood flowing out is usually very small, so there is no need to over-worry.