Blood in the nose is usually not related to the lungs. Possible causes are: dry weather, trauma, acute and chronic rhinitis, swelling in the nasal cavity and other diseases. 1. Dry weather: the weather is too dry, resulting in dry nasal mucosa, easy to rupture bleeding, showing the situation of blood in the nasal mucus. 2. Trauma: such as digging the nose too deep, resulting in nosebleed, and the above performance. 3. Rhinitis: at this time, due to the congestion of nasal mucosa, it is easy to lead to the rupture of blood vessels in the nasal mucosa, and the situation of blood in the nasal mucus appears. 4. Nasopharyngeal tumors: such as nasal septal capillary hemangioma, nasopharyngeal angiofibroma, hemorrhagic polyps, etc. are prone to nosebleed. 5. Diseases: such as liver disease, blood system diseases, thrombocytopenia, aplastic anemia and other coagulation disorders that lead to nosebleeds. If there is blood in the nasal mucus, you need to consult a doctor in time, and the cause of the disease will be clarified through the doctor’s examination and then treated symptomatically.