problem vs can of worms

problem and can of worms both are nouns.

Word	Noun	Adjective	Verb	Adverb
problem	Yes	No	No	No
can of worms	Yes	No	No	No

As nouns, can of worms is a hyponym of problem; that is, can of worms is a word with a more specific, narrower meaning than problem:

Other hyponyms of problem include pressure point, deep water, growing pains, hydra, matter.

problem (noun)	can of worms (noun)
a source of difficulty	a source of unpredictable trouble and complexity
a question raised for consideration or solution
a state of difficulty that needs to be resolved