swell up vs bloat

swell up is not a noun while bloat is a noun.

Word	Noun	Adjective	Verb	Adverb
swell up	No	No	Yes	No
bloat	Yes	No	Yes	No

As verbs, bloat is a hyponym of swell up; that is, bloat is a word with a more specific, narrower meaning than swell up:

Other hyponyms of swell up include distend, belly, belly out, blow up, puff, puff out, puff up, blister, vesicate.

swell up (noun)	bloat (noun)
	swelling of the rumen or intestinal tract of domestic animals caused by excessive gas

swell up (verb)	bloat (verb)
expand abnormally	become bloated or swollen or puff up
	make bloated or swollen