dyspnoea vs SOB

dyspnoea and SOB both are nouns.

Word	Noun	Adjective	Verb	Adverb
dyspnoea	Yes	No	No	No
SOB	Yes	No	No	No

As nouns, SOB is a hyponym of dyspnoea; that is, SOB is a word with a more specific, narrower meaning than dyspnoea:

Other hyponyms of dyspnoea include orthopnea, breathlessness, shortness of breath.

dyspnoea (noun)	SOB (noun)
difficult or labored respiration	insulting terms of address for people who are stupid or irritating or ridiculous
	a dyspneic condition