Nasal air odor may be related to atrophic rhinitis, sinusitis, nasal malignant tumors and other reasons. 1. Atrophic rhinitis: due to atrophic lesions in the nasal tissues, it can cause dryness of the nasal cavity and throat, nasal congestion and other symptoms, and in severe or advanced cases, the phenomenon of foul-smelling nostrils can occur. 2. Sinusitis: due to bacterial infection and inflammation of the stimulation effect, can cause nasal secretion increase, secretion in the nasal cavity after accumulating for a long time, it is easy to produce odor. 3. Nasal malignant tumor: tumor tissue necrosis in the nasal cavity can cause nasal odor. It is recommended to go to the hospital in time for the person with smelly nostrils, to clarify the cause of the disease, and to carry out standardized treatment under the guidance of the doctor.