lightheadedness vs dizziness

lightheadedness and dizziness both are nouns.

Word	Noun	Adjective	Verb	Adverb
lightheadedness	Yes	No	No	No
dizziness	Yes	No	No	No

As nouns, lightheadedness and dizziness are synonyms defined as:

lightheadedness and dizziness: a reeling sensation; a feeling that you are about to fall

Other synonyms of lightheadedness include giddiness, vertigo.

lightheadedness (noun)	dizziness (noun)
a frivolous lack of prudence	a reeling sensation; a feeling that you are about to fall
a reeling sensation; a feeling that you are about to fall