Frequent bleeding from the left nasal cavity is more likely to be caused by nasal diseases, such as inflammatory infections, trauma, and benign vascular lesions in the nasal cavity. First of all, we should improve the nasal endoscopy, observe the whole nasal cavity from front to back, look for the bleeding site, and if there is an exact bleeding point or a clear vascular disease, it is recommended to perform surgical treatment, which can be done by electrocoagulation to stop bleeding or nasal mass removal. The nature of the lesion should be clarified by combining pathological analysis. If there is no obvious bleeding site, it is recommended to use saline nasal spray, which can keep the mucosa moist and also promote further recovery of mucosal function. In case of obvious nasal inflammatory diseases, glucocorticoid-based nasal sprays can be used locally, which have good anti-inflammatory and anti-allergic effects and can reduce the edema of the mucosa and avoid vasodilation. Appropriate systemic administration of vitamins is beneficial to improve the permeability and fragility of blood vessels and avoid recurrent episodes of rhinorrhea.