The lack of smell in the nose indicates the presence of olfactory disorders, which can be divided into conductive olfactory disorders, sensory neurological olfactory disorders, central olfactory disorders, and may be related to nasal sinus inflammation, viral infections, brain tumors and other factors. 1. Conductive olfactory dysfunction: for example, nasal sinus inflammation, nasal sinus swelling, nasal foreign body, etc., may affect the binding of odor molecules with olfactory receptors, and conductive olfactory dysfunction will occur. 2. Sensorineural olfactory disorder: for example, viral infections, chemical poisons or head trauma may lead to olfactory epithelial damage or olfactory nerve damage, which may cause olfactory disorder. 3. Central olfactory dysfunction: for example, congenital olfactory dysfunction, neurodegenerative changes, brain tumors, etc., may lead to damage to the higher olfactory central nerves, which may cause central olfactory dysfunction. The lack of smell in the nose may also be due to other reasons, and it is recommended to consult a doctor in time for appropriate examination and treatment.