stress vs tension

stress and tension both are nouns.

Word	Noun	Adjective	Verb	Adverb
stress	Yes	No	Yes	No
tension	Yes	No	No	No

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

stress: (physics) force that produces strain on a physical body
tension: (physics) a stress that produces an elongation of an elastic physical body

Other hyponyms of stress include breaking point, mechanical stress.

As nouns, stress and tension are synonyms defined as:

stress and tension: (psychology) a state of mental or emotional strain or suspense

Other synonyms of stress include tenseness.

stress (noun)	tension (noun)
the relative prominence of a syllable or musical note (especially with regard to stress or pitch)	the action of stretching something tight
(physics) force that produces strain on a physical body	(physics) a stress that produces an elongation of an elastic physical body
(psychology) a state of mental or emotional strain or suspense	feelings of hostility that are not manifest
difficulty that causes worry or emotional tension	the physical condition of being stretched or strained
special emphasis attached to something	a balance between and interplay of opposing elements or tendencies (especially in art or literature)
	(psychology) a state of mental or emotional strain or suspense

stress (verb)	tension (verb)
to suffer from stress
to stress, single out as important
put stress on; utter with an accent
test the limits of