arthritic vs patient

arthritic and patient both are nouns.

Word	Noun	Adjective	Verb	Adverb
arthritic	Yes	Yes	No	No
patient	Yes	Yes	No	No

As nouns, patient is a hypernym of arthritic; that is, patient is a word with a broader meaning than arthritic:

arthritic (noun)	patient (noun)
a person afflicted with arthritis	the semantic role of an entity that is not the agent but is directly involved in or affected by the happening denoted by the verb in the clause
	a person who requires medical care

arthritic (adjective)	patient (adjective)
of or pertaining to arthritis	enduring trying circumstances with even temper or characterized by such endurance