hypervolemia vs blood disorder

hypervolemia and blood disorder both are nouns.

Word	Noun	Adjective	Verb	Adverb
hypervolemia	Yes	No	No	No
blood disorder	Yes	No	No	No

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

hypervolemia: a blood disorder consisting of an increase in the volume of circulating blood
blood disorder: a disease or disorder of the blood

Other hypernyms of hypervolemia include blood disease.

hypervolemia (noun)	blood disorder (noun)
a blood disorder consisting of an increase in the volume of circulating blood	a disease or disorder of the blood