A smell in the nose may be caused by odontogenic maxillary sinusitis, fungal sinusitis, nasal tumors and other causes. 1 Odontogenic maxillary sinusitis: acute inflammatory disease of the maxillary sinus mucosa due to dental caries and other causes. Manifestation of nasal congestion, runny nose, pus more with putrid odor, olfactory impairment, headache or pressure sensation. 2. Fungal sinusitis: fungal infection leads to congestion and swelling of the nasal mucosa, nasal secretions will be more than usual. The secretion is mostly yellowish-green and thick, accompanied by odor, so the nose smells like a flavor. 3. Nasal tumor: Nasal tumor grows too fast, local hemorrhage, necrosis and other reasons cause the tumor to ulcerate, resulting in a smell of the nose. When there is a smell from the nose, you should go to the ear, nose and throat department of the hospital in time for medical examination and take appropriate treatment according to the doctor’s suggestion.