blood relation vs blood relative

blood relation and blood relative both are nouns.

Word	Noun	Adjective	Verb	Adverb
blood relation	Yes	No	No	No
blood relative	Yes	No	No	No

As nouns, blood relation and blood relative are synonyms defined as:

blood relation and blood relative: one related by blood or origin; especially on sharing an ancestor with another

Other synonyms of blood relation include cognate, sib.

blood relation (noun)	blood relative (noun)
one related by blood or origin; especially on sharing an ancestor with another	one related by blood or origin; especially on sharing an ancestor with another