disqualification vs unfitness

disqualification and unfitness both are nouns.

Word	Noun	Adjective	Verb	Adverb
disqualification	Yes	No	No	No
unfitness	Yes	No	No	No

As nouns, unfitness is a hypernym of disqualification; that is, unfitness is a word with a broader meaning than disqualification:

disqualification (noun)	unfitness (noun)
the act of preventing someone from participating by finding them unqualified	the quality of not being suitable
unfitness that bars you from participation	lacking the power to perform
	poor physical condition; being out of shape or out of condition (as from a life of ease and luxury)