hypovolemia vs blood disease

hypovolemia and blood disease both are nouns.

Word	Noun	Adjective	Verb	Adverb
hypovolemia	Yes	No	No	No
blood disease	Yes	No	No	No

As nouns, blood disease is a hypernym of hypovolemia; that is, blood disease is a word with a broader meaning than hypovolemia:

hypovolemia: a blood disorder consisting of a decrease in the volume of circulating blood
blood disease: a disease or disorder of the blood

Other hypernyms of hypovolemia include blood disorder.

hypovolemia (noun)	blood disease (noun)
a blood disorder consisting of a decrease in the volume of circulating blood	a disease or disorder of the blood