blood type vs blood group

blood type and blood group both are nouns.

Word	Noun	Adjective	Verb	Adverb
blood type	Yes	No	No	No
blood group	Yes	No	No	No

As nouns, blood type and blood group are synonyms defined as:

blood type and blood group: human blood cells (usually just the red blood cells) that have the same antigens

blood type (noun)	blood group (noun)
human blood cells (usually just the red blood cells) that have the same antigens	human blood cells (usually just the red blood cells) that have the same antigens