respiratory tract infection vs respiratory infection

respiratory tract infection and respiratory infection both are nouns.

Word	Noun	Adjective	Verb	Adverb
respiratory tract infection	Yes	No	No	No
respiratory infection	Yes	No	No	No

As nouns, respiratory tract infection and respiratory infection are synonyms defined as:

respiratory tract infection and respiratory infection: any infection of the respiratory tract

respiratory tract infection (noun)	respiratory infection (noun)
any infection of the respiratory tract	any infection of the respiratory tract