kidney failure vs renal failure

kidney failure and renal failure both are nouns.

Word	Noun	Adjective	Verb	Adverb
kidney failure	Yes	No	No	No
renal failure	Yes	No	No	No

As nouns, kidney failure and renal failure are synonyms defined as:

kidney failure and renal failure: inability of the kidneys to excrete wastes and to help maintain the electrolyte balance

kidney failure (noun)	renal failure (noun)
inability of the kidneys to excrete wastes and to help maintain the electrolyte balance	inability of the kidneys to excrete wastes and to help maintain the electrolyte balance