Dysosmia

Olfactory dysfunction refers to an abnormal perception of odors caused by organic and/or functional lesions at various points along the olfactory pathway during the process of odor reception, transmission, and information analysis and integration. There are many causes of olfactory dysfunction, among which upper respiratory tract infections, nasal/sinus diseases, and head trauma are the main reasons. In addition, toxins or drugs and congenital factors also account for a certain proportion. The main symptoms include hyposmia, anosmia, olfactory agnosia, parosmia, phantosmia, and increased sensitivity to olfactory stimuli.