nerves vs mental state

nerves and mental state both are nouns.

Word	Noun	Adjective	Verb	Adverb
nerves	Yes	No	No	No
mental state	Yes	No	No	No

As nouns, mental state is a hypernym of nerves; that is, mental state is a word with a broader meaning than nerves:

nerves: an uneasy psychological state
mental state: (psychology) a mental condition in which the qualities of a state are relatively constant even though the state itself may be dynamic

Other hypernyms of nerves include mental condition, psychological condition, psychological state.

nerves (noun)	mental state (noun)
control of your emotions	(psychology) a mental condition in which the qualities of a state are relatively constant even though the state itself may be dynamic
an uneasy psychological state