No sense of smell is also called olfactory disorder. When there is a problem with the sense of smell, you need to visit the ENT department in time to check the situation in the nasal cavity, whether it can be cured depends on different situations. Common causes include respiratory hyposmia, sensory hyposmia, hysterical hyposmia, etc. 1. Respiratory hyposmia: It is mainly caused by nasal obstruction that prevents odor from touching the mucous membrane in the olfactory area, common diseases include nasal and nasopharyngeal atresia, adhesions, nasal turbinate hypertrophy, nasal polyps, nasal septum deviation, sinusitis, allergic rhinitis, etc. After medication or surgery, the sense of smell can generally be restored or improved. The sense of smell can be restored or improved after medication or surgery. In addition, after total laryngectomy and tracheotomy, the respiratory airflow does not pass through the nasal cavity, which may also cause loss of smell, but it is not an organic lesion and does not need to be treated. 2. Sensory hyposmia: such as lesions of olfactory mucosa, olfactory nerve and other endings, it is difficult to recover from this condition, which can be treated with nerve-nourishing drugs and hyperbaric oxygen, but it cannot be guaranteed to be cured. 3. Hysterical olfactory disorder: it is mainly caused by the stimulation of olfactory center and olfactory bulb. It should be actively treated by psychological therapy, and it is possible to recover, but it is difficult to be cured completely. Loss of smell caused by cold can be treated with nasal spray, antibiotics and hormone drugs, and the sense of smell may be restored after the acute inflammation is cured.