bends vs illness

bends and illness both are nouns.

Word	Noun	Adjective	Verb	Adverb
bends	Yes	No	No	No
illness	Yes	No	No	No

As nouns, illness is a hypernym of bends; that is, illness is a word with a broader meaning than bends:

bends: pain resulting from rapid change in pressure
illness: impairment of normal physiological function affecting part or all of an organism

Other hypernyms of bends include malady, sickness, unwellness.

bends (noun)	illness (noun)
pain resulting from rapid change in pressure	impairment of normal physiological function affecting part or all of an organism