Sudden sensitivity of sense of smell can be caused by hormonal changes, tumor diseases, nasal diseases and other factors. 1. Hormonal changes: Hormonal changes are common in menstruation and pregnancy, puerperium, menopause women, the hormone in the body can undergo a big change, which can make the sensitivity of sense of smell enhanced. 2. Tumor disease: glioma, metastatic tumor, meningioma and other brain tumors, due to the infiltration and erosion of the tumor, can involve the olfactory center and the olfactory bulb, resulting in the emergence of olfactory sensitivity or impairment of abnormal performance. 3. Nasal cavity disease: after the nasal cavity has been obstructive or inflammatory for a long time, when the obstructive factors are lifted and the inflammation is controlled, the sensitivity of sense of smell can be enhanced. When the sense of smell suddenly becomes sensitive, it is necessary to consult a doctor in time, and under the guidance of specialists, actively carry out appropriate treatment.