Frequent bleeding from one nostril may be caused by nose picking, nasal hemangioma or deviated nasal septum. 1. Nose picking: if you often pick one side of the nostril, it will easily lead to rupture of the mucous membrane of the nasal cavity and rupture of capillaries, thus causing bleeding. 2. Nasal hemangioma: it may be due to the presence of hemangioma in one side of the nasal cavity, when the hemangioma ruptures, it will easily lead to nosebleed. 3. Nasal septum deviation: mild nasal septum deviation usually does not easily lead to nosebleeds, but may be caused by a severe deviation of the nasal septum to one side of the phenomenon. A nostril often bleeds, there may be other causes, it is recommended to go to the hospital in a timely manner to identify the cause of the targeted treatment.