swelled head vs conceitedness

swelled head and conceitedness both are nouns.

Word	Noun	Adjective	Verb	Adverb
swelled head	Yes	No	No	No
conceitedness	Yes	No	No	No

As nouns, conceitedness is a hypernym of swelled head; that is, conceitedness is a word with a broader meaning than swelled head:

Other hypernyms of swelled head include conceit, vanity.

swelled head (noun)	conceitedness (noun)
an exaggerated opinion of your own importance	the trait of being unduly vain and conceited; false pride