blockage vs impediment

blockage and impediment both are nouns.

Word	Noun	Adjective	Verb	Adverb
blockage	Yes	No	No	No
impediment	Yes	No	No	No

As nouns, impediment is a hypernym of blockage; that is, impediment is a word with a broader meaning than blockage:

Other hypernyms of blockage include impedimenta, obstructer, obstruction, obstructor.

blockage (noun)	impediment (noun)
the act of blocking	any structure that makes progress difficult
an obstruction in a pipe or tube	something immaterial that interferes with or delays action or progress
the physical condition of blocking or filling a passage with an obstruction