respiratory illness vs respiratory disorder

respiratory illness and respiratory disorder both are nouns.

Word	Noun	Adjective	Verb	Adverb
respiratory illness	Yes	No	No	No
respiratory disorder	Yes	No	No	No

As nouns, respiratory illness and respiratory disorder are synonyms defined as:

respiratory illness and respiratory disorder: a disease affecting the respiratory system

Other synonyms of respiratory illness include respiratory disease.

respiratory illness (noun)	respiratory disorder (noun)
a disease affecting the respiratory system	a disease affecting the respiratory system