mastoiditis vs redness

mastoiditis and redness both are nouns.

Word	Noun	Adjective	Verb	Adverb
mastoiditis	Yes	No	No	No
redness	Yes	No	No	No

As nouns, redness is a hypernym of mastoiditis; that is, redness is a word with a broader meaning than mastoiditis:

mastoiditis: inflammation of the mastoid
redness: a response of body tissues to injury or irritation; characterized by pain and swelling and redness and heat

Other hypernyms of mastoiditis include inflammation, rubor.

mastoiditis (noun)	redness (noun)
inflammation of the mastoid	red color or pigment; the chromatic color resembling the hue of blood
	a response of body tissues to injury or irritation; characterized by pain and swelling and redness and heat