hemodialysis vs dialysis

hemodialysis and dialysis both are nouns.

Word	Noun	Adjective	Verb	Adverb
hemodialysis	Yes	No	No	No
dialysis	Yes	No	No	No

As nouns, dialysis is a hypernym of hemodialysis; that is, dialysis is a word with a broader meaning than hemodialysis:

hemodialysis: dialysis of the blood to remove toxic substances or metabolic wastes from the bloodstream; used in the case of kidney failure
dialysis: separation of substances in solution by means of their unequal diffusion through semipermeable membranes

hemodialysis (noun)	dialysis (noun)
dialysis of the blood to remove toxic substances or metabolic wastes from the bloodstream; used in the case of kidney failure	separation of substances in solution by means of their unequal diffusion through semipermeable membranes