Nosebleeds in boys may be caused by dry nasal cavity, nasal inflammation, nasal trauma and other factors. 1. Nasal cavity dryness: If the mucous membrane in the nasal cavity is dry, it may lead to the rupture of blood vessels under the mucous membrane and bleeding. You can use saline rinse, can also use compound menthol nasal drops to relieve nasal dryness. 2. Nasal inflammation: If you suffer from dry rhinitis, atrophic rhinitis and other diseases, the dryness and atrophy of the nasal mucosa may lead to nosebleeds. 3. Nasal trauma: the nose is hit, picking the nose, etc. may lead to nasal mucous membrane damage, nasal pain, nosebleed, usually within a short period of time will stop bleeding. In addition, sinusitis, nasal sinus tumor, nasal septum deviation can also cause nosebleeds, such as frequent nosebleeds should actively seek medical advice to clarify the diagnosis, and follow the doctor’s instructions to standardize the use of drugs and treatment.