There are many possible causes for the symptoms of nasal congestion on the left side of the nose. Patients may have acute and chronic rhinitis, acute and chronic sinusitis, allergic rhinitis and other conditions, which may trigger the symptoms of nasal congestion on the left side of the nostril. Some patients may have more inflammatory secretions accumulated in the nasal passages, which may aggravate the symptoms of nasal congestion. At the same time, some patients may also have obvious deviation of the nasal septum or abnormal growths such as polyps and papillomas in the left nasal cavity, which may easily cause the symptoms of nasal non-ventilation on the left side. If such non-ventilation symptoms are recurrent or persistent, it is necessary to pay attention to further detailed examination to clarify the cause.