shortness of breath vs dyspnoea

shortness of breath and dyspnoea both are nouns.

Word	Noun	Adjective	Verb	Adverb
shortness of breath	Yes	No	No	No
dyspnoea	Yes	No	No	No

As nouns, dyspnoea is a hypernym of shortness of breath; that is, dyspnoea is a word with a broader meaning than shortness of breath:

Other hypernyms of shortness of breath include dyspnea.

shortness of breath (noun)	dyspnoea (noun)
a dyspneic condition	difficult or labored respiration