fatigue fracture vs stress fracture

fatigue fracture and stress fracture both are nouns.

Word	Noun	Adjective	Verb	Adverb
fatigue fracture	Yes	No	No	No
stress fracture	Yes	No	No	No

As nouns, fatigue fracture and stress fracture are synonyms defined as:

fatigue fracture and stress fracture: fracture resulting from excessive activity rather than a specific injury

fatigue fracture (noun)	stress fracture (noun)
fracture resulting from excessive activity rather than a specific injury	fracture resulting from excessive activity rather than a specific injury