Total bleeding from unilateral nostril is commonly seen in nasal hemangioma, deviated nasal septum, nasopharyngeal carcinoma and so on. 1. Nasal hemangioma: Nasal hemangioma is a prominent manifestation of nasal hemangioma as recurrent intermittent nosebleed, the amount of bleeding varies each time, and those with much bleeding may have secondary anemia. 2. Deviated nasal septum: because the lesion is located in the convex surface or spine and ridge of deviated nasal septum, the mucous membrane in this place is more tense and thin, coupled with the rich blood supply in the soft tissue in front of nasal septum, it is easy to bleed, and thus there is the phenomenon of unilateral bleeding from one side of the nostril. 3. Nasal cavity malignant tumor: mostly secondary to the direct spread of malignant tumors in the sinuses, external nose, orbit, nasopharynx and other places. Symptoms are mostly unilateral snot blood, nasal congestion and other non-specific nasal manifestations. Unilateral total bleeding from the nostrils can also be common for other reasons, it is recommended to seek early medical attention to clarify the cause.