dyspepsia vs indigestion

dyspepsia and indigestion both are nouns.

Word	Noun	Adjective	Verb	Adverb
dyspepsia	Yes	No	No	No
indigestion	Yes	No	No	No

As nouns, dyspepsia and indigestion are synonyms defined as:

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

Other synonyms of dyspepsia include stomach upset, upset stomach.

dyspepsia (noun)	indigestion (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