cephalalgia vs aching

cephalalgia and aching both are nouns.

Word	Noun	Adjective	Verb	Adverb
cephalalgia	Yes	No	No	No
aching	Yes	Yes	No	No

As nouns, aching is a hypernym of cephalalgia; that is, aching is a word with a broader meaning than cephalalgia:

cephalalgia: pain in the head caused by dilation of cerebral arteries or muscle contractions or a reaction to drugs
aching: a dull persistent (usually moderately intense) pain

Other hypernyms of cephalalgia include ache.

cephalalgia (noun)	aching (noun)
pain in the head caused by dilation of cerebral arteries or muscle contractions or a reaction to drugs	a dull persistent (usually moderately intense) pain

cephalalgia (adjective)	aching (adjective)
	causing a dull and steady pain