hygiene vs medical specialty

hygiene and medical specialty both are nouns.

Word	Noun	Adjective	Verb	Adverb
hygiene	Yes	No	No	No
medical specialty	Yes	No	No	No

As nouns, medical specialty is a hypernym of hygiene; that is, medical specialty is a word with a broader meaning than hygiene:

hygiene: the science concerned with the prevention of illness and maintenance of health
medical specialty: the branches of medical science that deal with nonsurgical techniques

Other hypernyms of hygiene include medicine.

hygiene (noun)	medical specialty (noun)
the science concerned with the prevention of illness and maintenance of health	the branches of medical science that deal with nonsurgical techniques
a condition promoting sanitary practices