ischemic stroke vs ischaemia

ischemic stroke and ischaemia both are nouns.

Word	Noun	Adjective	Verb	Adverb
ischemic stroke	Yes	No	No	No
ischaemia	Yes	No	No	No

As nouns, ischaemia is a hypernym of ischemic stroke; that is, ischaemia is a word with a broader meaning than ischemic stroke:

ischemic stroke: the most common kind of stroke; caused by an interruption in the flow of blood to the brain (as from a clot blocking a blood vessel)
ischaemia: local anemia in a given body part sometimes resulting from vasoconstriction or thrombosis or embolism

Other hypernyms of ischemic stroke include apoplexy, cerebrovascular accident, CVA, stroke, ischemia.

ischemic stroke (noun)	ischaemia (noun)
the most common kind of stroke; caused by an interruption in the flow of blood to the brain (as from a clot blocking a blood vessel)	local anemia in a given body part sometimes resulting from vasoconstriction or thrombosis or embolism