nocturia vs nycturia

nocturia and nycturia both are nouns.

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

As nouns, nocturia and nycturia are synonyms defined as:

nocturia and nycturia: excessive urination at night; especially common in older men

nocturia (noun)	nycturia (noun)
excessive urination at night; especially common in older men	excessive urination at night; especially common in older men