micturition vs nycturia

micturition and nycturia both are nouns.

Word	Noun	Adjective	Verb	Adverb
micturition	Yes	No	No	No
nycturia	Yes	No	No	No

As nouns, nycturia is a hyponym of micturition; that is, nycturia is a word with a more specific, narrower meaning than micturition:

Other hyponyms of micturition include leak, making water, passing water, wetting, lithuresis, nocturia, oliguria, pee, peeing, piss, pissing.

micturition (noun)	nycturia (noun)
the discharge of urine	excessive urination at night; especially common in older men