personal matters vs affairs

personal matters and affairs both are nouns.

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

As nouns, personal matters and affairs are synonyms defined as:

Other synonyms of personal matters include personal business.

personal matters (noun)	affairs (noun)
matters of personal concern	transactions of professional or public interest
	matters of personal concern