NREM sleep vs NREM

NREM sleep and NREM both are nouns.

Word	Noun	Adjective	Verb	Adverb
NREM sleep	Yes	No	No	No
NREM	Yes	No	No	No

As nouns, NREM sleep and NREM are synonyms defined as:

NREM sleep and NREM: a recurring sleep state during which rapid eye movements do not occur and dreaming does not occur; accounts for about 75% of normal sleep time

Other synonyms of NREM sleep include nonrapid eye movement, nonrapid eye movement sleep, orthodox sleep.

NREM sleep (noun)	NREM (noun)
a recurring sleep state during which rapid eye movements do not occur and dreaming does not occur; accounts for about 75% of normal sleep time	a recurring sleep state during which rapid eye movements do not occur and dreaming does not occur; accounts for about 75% of normal sleep time