Nasal congestion is usually caused by inflammatory diseases, structural abnormalities of the nasal cavity, nasal cavity occupation and other reasons. 1. Inflammatory diseases: acute and chronic rhinitis, allergic rhinitis, sinusitis and other inflammatory diseases lead to congestion and edema of the mucous membrane of bilateral turbinate, blocking the nasal cavity, and intermittent and alternating symptoms of nasal congestion. 2. Abnormal nasal structure: Nasal anatomical deformities can also lead to nasal congestion. For example, in the case of deviated nasal septum, the nasal septum is morphologically deviated to one side or both sides, or locally protruded, causing nasal cavity dysfunction and nasal congestion symptoms. 3. Nasal cavity occupying position: Nasal cavity occupying position due to blockage of nasal cavity by foreign body, nasal polyp, nasal tumor, adenoid hypertrophy and nasopharyngeal carcinoma occupying position of nasopharyngeal area, all of which will cause nasal congestion symptoms. Nasal congestion symptoms suggest timely medical treatment, under the guidance of the doctor to clarify the diagnosis, targeted treatment.