The inability of the nose to smell indicates the presence of olfactory disorders, which may be caused by upper respiratory tract infections, nasal polyps, sinusitis, central neuropathy, olfactory nerve damage and other causes. 1. Upper respiratory tract infection: If you suffer from acute upper respiratory tract infection, the inflammation will lead to edema in the olfactory region or trigger olfactory neuritis, which may result in the nose not being able to smell the flavor. 2. Nasal polyps: due to severe swelling and edema of the nasal mucosa, resulting in the appearance of nasal polyps, nasal polyps will prevent the odor from reaching the olfactory mucosa area, so that it can not be perceived by the olfactory nerve endings. Therefore, the phenomenon of the nose can not smell the flavor. 3. Sinusitis: due to chronic inflammation of the nasal cavity and colds caused by sinusitis, may cause congestion and hypertrophy of the nasal and sinus mucosa and oppression of the olfactory region, so the phenomenon of the nose can not smell the taste. 4. Neuropathy of the central nervous system: due to the lesion of the central olfactory nerve, the stimulus obtained by the olfactory receptors can not be transmitted to the central nervous system, which leads to the phenomenon that the nose can not smell the flavor. 5. Olfactory nerve damage: due to viral infections, chemical poisons, head trauma and other causes of olfactory nerve damage, affecting the normal olfactory function, so the nose can not smell the flavor. When the phenomenon of not being able to smell the smell of the nose occurs, you should go to the hospital in time, and standardize the treatment after the diagnosis is clear.