The symptoms of nosebleed when the patient lowers his head, mainly due to the local mucous membrane of the nasal cavity, a certain degree of erosion, rupture of the condition, when the head is easy to cause blood pressure increases, it is easy to rupture the blood vessels, causing the symptoms of bleeding. At the same time, some patients may also have a certain degree of inflammation of the nasal cavity, sinuses, as well as allergic diseases, which can easily cause nasal mucosa congestion, swelling, edema. Repeatedly picking the nose and rubbing the nose may also cause ulceration and erosion of the nasal mucosa. Some patients may also have obvious deviation of the nasal septum, and there may be hemangiomas, hemorrhagic polyps and other proliferations in the nasal cavity, all of which may cause nosebleeds when bowing the head, and require further careful and comprehensive examination of the nose if necessary.