damage vs impairment

damage and impairment both are nouns.

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

As nouns, impairment is a hyponym of damage; that is, impairment is a word with a more specific, narrower meaning than damage:

Other hyponyms of damage include defacement, disfiguration, disfigurement, mutilation, wound, wounding, burn, defloration.

As nouns, damage and impairment are synonyms defined as:

Other synonyms of damage include harm.

damage (noun)	impairment (noun)
the act of damaging something or someone	damage that results in a reduction of strength or quality
any harm or injury resulting from a violation of a legal right	the act of making something futile and useless (as by routine)
the occurrence of a change for the worse	the occurrence of a change for the worse
loss of military equipment	the condition of being unable to perform as a consequence of physical or mental unfitness
the amount of money needed to purchase something	a symptom of reduced quality or strength

damage (verb)	impairment (verb)
inflict damage upon
suffer or be susceptible to damage