The etiology of blood in nose blowing is more complicated, and the common ones are dry-atrophic rhinitis, sinus disease, nasopharyngeal occupation and so on. 1. Dry – atrophic rhinitis: dry rhinitis and atrophic rhinitis, nasal mucosa dry and thin, increased vascular fragility, due to nose picking, nose blowing, etc. easily caused by the nasal mucosa damage, the less serious can be manifested by blowing the nose with blood in the nasal mucus to improve the bad habits, the serious can be relieved by local nasal medication. 2. Sinus disease: If there is fungal sinusitis, when the mucosa and bone wall are invaded by fungus, there may be intranasal bleeding, and there may be blood or blood clot when blowing the nose in the early stage. 3. Nasopharyngeal space occupation: Nasopharyngeal cancer patients often have blood in the nasal mucus when blowing the nose in the early stage, which occurs sometimes, and with the progress of the disease, intranasal bleeding can be repeated when the capillaries are ruptured. Therefore, it is recommended to consult doctor in time when nasal discomfort occurs, so as to clarify the cause of disease and carry out targeted treatment.