nervous strain vs mental strain

nervous strain and mental strain both are nouns.

Word	Noun	Adjective	Verb	Adverb
nervous strain	Yes	No	No	No
mental strain	Yes	No	No	No

As nouns, nervous strain and mental strain are synonyms defined as:

nervous strain and mental strain: (psychology) nervousness resulting from mental stress

Other synonyms of nervous strain include strain.

nervous strain (noun)	mental strain (noun)
(psychology) nervousness resulting from mental stress	(psychology) nervousness resulting from mental stress