Olfactory neuritis may be related to infection, etc. It manifests as symptoms such as hyposmia, phantom smell, olfactory deficit, olfactory inversion, and loss of smell. 1. Olfactory hypoplasia: it can be manifested as decreased sensitivity to stimuli such as surrounding odors. 2. Phantom smell: When there is no objective odor stimulation around, the patient smells an unpleasant odor that cannot be described. 3. Olfactory deficits: severe cases may result in no response to odor stimulation. 4. Olfactory inversion: Misplaced response to stimuli such as odors, but no impairment of olfactory acuity. 5. Loss of olfaction: Some severe cases may have olfactory impairment and loss of response to odor stimuli. If you find symptoms of olfactory neuritis, you need to go to a regular hospital and get treatment under the doctor’s guidance, so as not to delay the condition.