olfactory impairment vs dysosmia

olfactory impairment and dysosmia both are nouns.

Word	Noun	Adjective	Verb	Adverb
olfactory impairment	Yes	No	No	No
dysosmia	Yes	No	No	No

As nouns, olfactory impairment and dysosmia are synonyms defined as:

Other synonyms of olfactory impairment include parosamia.

olfactory impairment (noun)	dysosmia (noun)
a disorder in the sense of smell	a disorder in the sense of smell