upsurge vs increase

upsurge and increase both are nouns.

Word	Noun	Adjective	Verb	Adverb
upsurge	Yes	No	No	No
increase	Yes	No	Yes	No

As nouns, increase is a hypernym of upsurge; that is, increase is a word with a broader meaning than upsurge:

Other hypernyms of upsurge include step-up.

upsurge (noun)	increase (noun)
a sudden or abrupt strong increase	the act of increasing something
a sudden forceful flow	the amount by which something increases
	a change resulting in an increase
	a process of becoming larger or longer or more numerous or more important
	a quantity that is added

upsurge (verb)	increase (verb)
	become bigger or greater in amount
	make bigger or more