Due to the anatomical structure of the nasal cavity, flies flying into the nose are usually fine, but there is a risk of infection. 1. Due to the protective mechanism of the nasal mucosa, having a fly into the nasal cavity can trigger sneezing, and the bugs can usually be sprayed out by sneezing. And the nose has the ability of self-protection, the nasal passage in the nasal cavity is curved, and the mucus secreted can cause flies to asphyxiate, mostly suffocate and die, which can be brought out of the nose with sneezing or snot. 2. If the fly is not discharged from the nasal cavity, it should be taken out by a doctor in time, if it is not taken out for a long time, there may be a risk of infection. If the fly may block the sinus opening, leading to poor sinus drainage, which in turn triggers an inflammatory reaction of the sinus mucosa. It is recommended that patients seek medical attention promptly after the fly flies into the nasal cavity, and remove the fly as soon as possible to avoid infection.