upset stomach vs dyspepsia

upset stomach and dyspepsia both are nouns.

Word	Noun	Adjective	Verb	Adverb
upset stomach	Yes	No	No	No
dyspepsia	Yes	No	No	No

As nouns, upset stomach and dyspepsia are synonyms defined as:

upset stomach and dyspepsia: a disorder of digestive function characterized by discomfort or heartburn or nausea

Other synonyms of upset stomach include indigestion, stomach upset.

upset stomach (noun)	dyspepsia (noun)
a disorder of digestive function characterized by discomfort or heartburn or nausea	a disorder of digestive function characterized by discomfort or heartburn or nausea