There are many reasons for the occurrence of nosebleeds when the head is bowed. The more common is capillary rupture bleeding inside the nasal cavity, some patients are due to picking the nose damage to the nasal mucosa, there may be due to bleeding nasal polyps, nasopharyngeal fibroangioma caused. Some patients are due to neoplastic lesions, such as nasal cavity, sinus involutional papilloma, and nasopharyngeal carcinoma, and some patients are due to hypertension, thrombocytopenia, leukemia and coagulation dysfunction, the specific cause of bleeding has a relatively large individual differences. After the onset of the disease, it is recommended to go to the Department of Otorhinolaryngology for consultation, and nasal endoscopy can be done to help clarify the lesions in the nasal cavity. Some patients also need to do blood routine, coagulation function test, to clarify the specific cause of bleeding, to check whether there is a blood disease, after clarifying the condition, you can carry out targeted treatment.