The presence of unilateral nasal congestion with clear nasal discharge can be caused by allergic rhinitis or deviated nasal septum, which needs to be combined with nasal endoscopy to observe the structure of the entire nasal cavity and the color of the mucous membrane. If the mucous membrane is pale and edematous, the possibility of allergic rhinitis is relatively high, because such diseases can lead to hypertrophy of the turbinates, while the presence of nasal cycles in the inferior turbinates will result in alternate expansion or reduction of the turbinates bilaterally within a certain period of time, and the above symptoms will occur. Deviated nasal septum can lead to unilateral narrowing of nasal air, and when the inferior turbinates are hypertrophied, it leads to further narrowing of the nasal space, and a large amount of clear watery nasal discharge can occur. Allergic rhinitis is more often treated with standardized medication to control symptoms, while deviated nasal septum is a structural abnormality, medication is ineffective and needs to be combined with sinus CT examination to develop a personalized surgical plan.