cephalalgia vs headache

cephalalgia and headache both are nouns.

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

As nouns, cephalalgia and headache are synonyms defined as:

cephalalgia and headache: pain in the head caused by dilation of cerebral arteries or muscle contractions or a reaction to drugs

Other synonyms of cephalalgia include head ache.

cephalalgia (noun)	headache (noun)
pain in the head caused by dilation of cerebral arteries or muscle contractions or a reaction to drugs	something or someone that causes anxiety; a source of unhappiness
	pain in the head caused by dilation of cerebral arteries or muscle contractions or a reaction to drugs