personal matters vs concern

personal matters and concern both are nouns.

Word	Noun	Adjective	Verb	Adverb
personal matters	Yes	No	No	No
concern	Yes	No	Yes	No

As nouns, concern is a hypernym of personal matters; that is, concern is a word with a broader meaning than personal matters:

personal matters: matters of personal concern
concern: something that interests you because it is important or affects you

personal matters (noun)	concern (noun)
matters of personal concern	something that interests you because it is important or affects you
	something or someone that causes anxiety; a source of unhappiness
	a feeling of sympathy for someone or something
	an anxious feeling
	a commercial or industrial enterprise and the people who constitute it

personal matters (verb)	concern (verb)
	be relevant to
	be on the mind of