Mr. Li had a cold a few months ago, and after he recovered from the cold, he often had a runny nose, which he did not care about. Finally, the old man underwent nasal polyp removal and maxillary sinus opening surgery under nasal endoscopy, which solved the old man’s pain. In fact, the old man had maxillary sinusitis, and among all sinuses, the maxillary sinus is more susceptible to infection, which is related to its own anatomical shape. Because the natural opening of the maxillary sinus is too high, it is the worst drainage condition among all sinuses; the high opening and low sinus cavity are not conducive to air exchange; the sinus cavity is large and the opening is small, and the ratio of the two is disparate, which also hinders drainage. In addition, because the opening of other sinuses is higher than the maxillary sinus, so it is also easy to be infected by the inflammation of other sinuses, plus the elderly nasal cilia function is weakened, Mr. Li has polyps in the nasal cavity, these factors lead to prolonged sinusitis in the elderly. Because of the large amount of purulent secretions in the sinuses, there will still be a lot of pus nasal discharge even when the cold is well, which will cause headaches over time, and the pus will have a foul odor produced in the sinus cavity. In terms of treatment, sinusitis not accompanied by nasal polyps can be treated conservatively, which is generally effective, and surgery can be considered for those who are not effective. Patients with sinusitis accompanied by nasal polyps need surgical treatment, and currently functional endoscopic sinus surgery is used, which can maximize the removal of lesions and restore the physiological function of the nose and sinuses.