pathology vs unhealthiness

pathology and unhealthiness both are nouns.

Word	Noun	Adjective	Verb	Adverb
pathology	Yes	No	No	No
unhealthiness	Yes	No	No	No

As nouns, unhealthiness is a hypernym of pathology; that is, unhealthiness is a word with a broader meaning than pathology:

pathology: any deviation from a healthy or normal condition
unhealthiness: a state in which you are unable to function normally and without pain

Other hypernyms of pathology include health problem, ill health.

pathology (noun)	unhealthiness (noun)
the branch of medical science that studies the causes and nature and effects of diseases	a state in which you are unable to function normally and without pain
any deviation from a healthy or normal condition