There are many causes for the patient’s two nostrils to breathe differently. First, the patient may have congenital deviated nasal septum, the volume of the two nasal cavities are not the same, sometimes one is bigger and one is smaller will lead to nasal ventilation and feel different. If one side of the inferior turbinate is enlarged, the ventilation of the nasal cavity on the other side will be worse. Thirdly, there may be new organisms formed in the nasal cavity of one side of the patient, mainly including nasal polyps, nasal papilloma, or malignant lymphoma, etc. Regardless of which of the above causes the two nostrils are not the same, you need to go to the hospital for a careful examination, and if necessary, you often need further symptomatic treatment, and the condition will improve after active treatment.