Nostril pus is mucosal pathological changes manifested as edema, thickening, vascular hyperplasia, lymphatic fine thorax and plasma cell infiltration, epithelial cilia detachment or squamous epithelial hyperplasia and polypoid changes, and if the secretory gland ducts are blocked, cystic changes can occur. There are many causes of pus in the nostrils, and patients need to clarify the cause of the disease before treatment, so as to ensure the effectiveness of the treatment. The causes of pus in the nostrils are as follows: There are many causes of pus in the nostrils, in addition to the causes of pus in the nostrils due to the body on fire, chronic suppurative sinusitis is also the main cause of pus in the nostrils, often secondary to respiratory tract infections or acute rhinitis. High deviation of the nasal septum, middle turbinate hypertrophy, nasal polyps, nasal tumors, foreign objects or fillings left in place for too long can prevent sinus drainage and cause disease. Swimming diving or diving method is not appropriate, can make the sewage through the nasal cavity into the sinuses and the onset of disease. In addition, the former group of sinuses, especially the maxillary sinus and frontal sinus location shallow, vulnerable to trauma and fracture, bacteria can be invaded by the skin or nasal mucosa sinus. Infection can also be caused by the entry of foreign objects such as shrapnel and dust, resulting in pus from the nostrils.