Nosebleed for no reason may be dry rhinitis, may also be related to leukemia, nasal capillary hemangioma and other diseases. 1. Dry rhinitis: if the patient of this disease is located in the environment of dry air and low humidity, it may be more likely than normal people to nasal mucosa appear dry, congestion and other changes. In the long run, it will cause the brittleness of capillaries to increase and rupture and bleed, so there will be symptoms of nosebleed for no reason. 2. Leukemia: It is a disease of hematopoietic system mainly caused by the stagnation of cells at different stages of development due to uncontrolled cell proliferation, impaired differentiation and blocked apoptosis. It often causes malaise, enlarged lymph nodes, abnormal nasal bleeding, anemia and other discomforts. 3. Nasal capillary hemangioma: when the nasal mucosa is thin, the nasal capillaries are elevated outside the mucosa to form a tumor-like bulge, and the vessel wall breaks down due to dryness, which will cause repeated bleeding from the nose. After causing this symptom, the patient should actively consult a doctor and do systematic examination to make a clear diagnosis.