bad luck vs circumstances

bad luck and circumstances both are nouns.

Word	Noun	Adjective	Verb	Adverb
bad luck	Yes	No	No	No
circumstances	Yes	No	No	No

As nouns, circumstances is a hypernym of bad luck; that is, circumstances is a word with a broader meaning than bad luck:

bad luck: an unfortunate state resulting from unfavorable outcomes
circumstances: your overall circumstances or condition in life (including everything that happens to you)

Other hypernyms of bad luck include destiny, fate, fortune, lot, luck, portion.

bad luck (noun)	circumstances (noun)
unnecessary and unforeseen trouble resulting from an unfortunate event	a person's financial situation (good or bad)
an unpredictable outcome that is unfortunate	your overall circumstances or condition in life (including everything that happens to you)
an unfortunate state resulting from unfavorable outcomes