lead poisoning vs sickness

lead poisoning and sickness both are nouns.

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

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

lead poisoning: toxic condition produced by the absorption of excessive lead into the system
sickness: impairment of normal physiological function affecting part or all of an organism

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

lead poisoning (noun)	sickness (noun)
toxic condition produced by the absorption of excessive lead into the system	impairment of normal physiological function affecting part or all of an organism
	the state that precedes vomiting
	defectiveness or unsoundness