swell up vs distend

swell up and distend both are verbs.

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

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

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

swell up (verb)	distend (verb)
expand abnormally	become wider
	swell from or as if from internal pressure
	cause to expand as if by internal pressure