Nasal congestion on one side and ventilation on the other side may be nasal septum curvature, chronic rhinitis, chronic sinusitis, etc., timely consultation to identify the cause of the disease. 1. Curvature of nasal septum: the development of the bones that make up the nasal septum is not balanced, resulting in different tension curves, leading to the septum to one side, so that one side of the nasal cavity is narrowed, poor ventilation, so there will be a side of the nasal congestion on the other side of the ventilation of the symptoms. 2. Chronic rhinitis: it is due to the body’s own endocrine or immune system disorders, infections, long-term use of local drugs caused by chronic congestion and hyperplasia of the nasal mucosal blood vessels, resulting in typical alternating nasal congestion, when lying on the side of the lower side of the nasal obstruction, the upper side of the nasal cavity ventilation, and then turn to the other side of the alternating situation, accompanied by a mild runny nose. 3. Chronic sinusitis: most of them are caused by upper respiratory tract infections or acute sinusitis, and the causative organisms are mostly purulent cocci. Sinusitis patients will show symptoms of nasal congestion on a fixed side, or may show alternating symptoms of nasal congestion. One side of the nasal congestion and ventilation, there may be other reasons, should be timely consultation, to clarify the specific causes, if necessary, the appropriate treatment.