cerebral edema vs hydrops

cerebral edema and hydrops both are nouns.

Word	Noun	Adjective	Verb	Adverb
cerebral edema	Yes	No	No	No
hydrops	Yes	No	No	No

As nouns, hydrops is a hypernym of cerebral edema; that is, hydrops is a word with a broader meaning than cerebral edema:

cerebral edema: swelling of the brain due to the uptake of water in the neuropile and white matter
hydrops: swelling from excessive accumulation of watery fluid in cells, tissues, or serous cavities

Other hypernyms of cerebral edema include dropsy, edema, oedema.

cerebral edema (noun)	hydrops (noun)
swelling of the brain due to the uptake of water in the neuropile and white matter	swelling from excessive accumulation of watery fluid in cells, tissues, or serous cavities