Sleeping on the left side of the nose on the left side is not ventilated, there may be chronic simple rhinitis, nasal polyps and other causes. 1. Chronic simple rhinitis: it can lead to intermittent or alternating nasal congestion, which is alleviated during the day or after activities, aggravated at night after sitting for a long time, and nasal congestion on the lower side when lying on the side. It can be treated by local use of ephedrine saline, furosemide nasal drops, or local use of procaine solution for inferior turbinate or nasal mound closure, local use of glucocorticoid sprays, such as budesonide nasal spray. 2. Nasal polyps: smaller polyps have no obvious symptoms, with the polyp increase will cause nasal congestion progressive aggravation, may lead to sleep on the left side of the nose on the left side of the ventilation. You can first standardize the use of nasal spray glucocorticosteroids, such as fluticasone propionate nasal spray treatment, such as conservative treatment is not effective, can be treated through the surgical removal of nasal polyps. It is recommended to go to the hospital for examination, to clarify the cause of the disease, and follow the doctor’s instructions for targeted medication and treatment.