get up vs heighten

get up and heighten both are verbs.

Word	Noun	Adjective	Verb	Adverb
get up	No	No	Yes	No
heighten	No	No	Yes	No

As verbs, heighten is a hyponym of get up; that is, heighten is a word with a more specific, narrower meaning than get up:

get up (verb)	heighten (verb)
get up and out of bed	increase the level of
cause to rise	become more extreme
put on special clothes to appear particularly appealing and attractive	make more extreme; raise in quantity, degree, or intensity
develop	make more intense, stronger, or more marked
study intensively, as before an exam	make (one's senses) more acute
arrange by systematic planning and united effort	increase the height of
raise from a lower to a higher position
rise to one's feet