food poisoning vs sickness

food poisoning and sickness both are nouns.

Word	Noun	Adjective	Verb	Adverb
food poisoning	Yes	No	No	No
sickness	Yes	No	No	No

As nouns, sickness is a hypernym of food poisoning; that is, sickness is a word with a broader meaning than food poisoning:

food poisoning: illness caused by poisonous or contaminated food
sickness: impairment of normal physiological function affecting part or all of an organism

Other hypernyms of food poisoning include illness, malady, unwellness.

food poisoning (noun)	sickness (noun)
illness caused by poisonous or contaminated food	impairment of normal physiological function affecting part or all of an organism
	the state that precedes vomiting
	defectiveness or unsoundness