myositis vs redness

myositis and redness both are nouns.

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

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

myositis: inflammation of muscle tissue
redness: a response of body tissues to injury or irritation; characterized by pain and swelling and redness and heat

Other hypernyms of myositis include inflammation, rubor.

myositis (noun)	redness (noun)
inflammation of muscle tissue	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