There are many causes of nosebleeds, which may be precursors of cancer, but they are generally rare. It is recommended to go to the ENT department of the hospital for examination in time to identify the cause and treat accordingly. Nosebleeds are commonly caused by nasal inflammation, such as dry rhinitis, acute rhinitis, sinusitis, etc. Some special infections, such as nasal tuberculosis and leprosy, can also be caused. Nasal contusions, cuts, lacerations and nose-digging injuries can also lead to nosebleeds when they occur. In addition, deviated nasal septum can easily cause nosebleeds due to the friction between nasal bone and nasal lateral wall and long-term stimulation of nasal septum by dry air, which can easily cause rupture and bleeding of mucosal vessels. In case of nasopharyngeal cancer, patients will not only have symptoms of recurrent nasal bleeding, but also be accompanied by morning nasal discharge with blood, stuffy ears, unilateral headache, etc. In addition to nasopharyngeal cancer, leukemia can also cause nosebleeds. If there is occasional nosebleed, don’t worry too much, it is mostly due to dry air, but if there is repeated nosebleed with other symptoms, it may be due to cancer and should be promptly seen by ENT or hematology department.