The main clinical diseases are the following: 1. sinusitis, which can be chronic or acute, mainly due to bacterial infection in the nasal cavity, protein decay, etc. The odor of the nasal cavity, in this case, generally speaking, after conservative treatment with sinusitis drugs, the patient odor will generally gradually ease. 2. atrophic rhinitis, such patients may be due to a large number of dry nasal cavity, crust, corruption and the formation of odorous nasal syndrome. 3. The nasal cavity has a foreign body, which is mostly seen in children, mostly unilateral nasal cavity blockage, with nasal odor, may be after the children’s nasal cavity plug foreign body, long-term local corruption and the formation of the nasal cavity may have a bad smell. In addition, some patients have lymphoma of the nasal cavity, cancer of the nasal cavity, malignant tumors, local erosion, ulceration, can appear nasal malodor.