deterioration vs impairment

deterioration and impairment both are nouns.

Word	Noun	Adjective	Verb	Adverb
deterioration	Yes	No	No	No
impairment	Yes	No	No	No

As nouns, deterioration and impairment are synonyms defined as:

deterioration (noun)	impairment (noun)
process of changing to an inferior state	damage that results in a reduction of strength or quality
a symptom of reduced quality or strength	the act of making something futile and useless (as by routine)
	the occurrence of a change for the worse
	the condition of being unable to perform as a consequence of physical or mental unfitness
	a symptom of reduced quality or strength