The reasons for the nose to be out of breath are rhinitis, sinusitis, and abnormalities in the internal structure of the nose. 1. Rhinitis: rhinitis caused by various reasons, nasal mucous membrane congestion, edema, mucus glands secrete mucus to increase the amount of blockage of the nasal cavity, resulting in the nose has not been ventilated. 2. Sinusitis: Inflammatory swelling of nasal mucosa in patients with sinusitis, coupled with a large amount of pus nasal secretion from mucous glands blocking the nasal cavity, the nose is swollen, and it is accompanied by decreased sense of smell. 3. Abnormalities in the nasal structure: deviated nasal septum, enlarged nasal turbinates caused by rhinitis, nasal polyps, nasal tumors, etc., the respiratory passages become narrower, and there is a situation that the nose is not ventilated all the time. If you have a problem with your nose, you should go to the hospital in time to find out the cause of the problem and give symptomatic treatment to improve the symptoms of the lack of ventilation.