postural hypotension vs orthostatic hypotension

postural hypotension and orthostatic hypotension both are nouns.

Word	Noun	Adjective	Verb	Adverb
postural hypotension	Yes	No	No	No
orthostatic hypotension	Yes	No	No	No

As nouns, postural hypotension and orthostatic hypotension are synonyms defined as:

postural hypotension and orthostatic hypotension: low blood pressure occurring in some people when they stand up

postural hypotension (noun)	orthostatic hypotension (noun)
low blood pressure occurring in some people when they stand up	low blood pressure occurring in some people when they stand up