sneezing vs symptom

sneezing and symptom both are nouns.

Word	Noun	Adjective	Verb	Adverb
sneezing	Yes	No	No	No
symptom	Yes	No	No	No

As nouns, symptom is a hypernym of sneezing; that is, symptom is a word with a broader meaning than sneezing:

sneezing: a symptom consisting of the involuntary expulsion of air from the nose
symptom: (medicine) any sensation or change in bodily function that is experienced by a patient and is associated with a particular disease

sneezing (noun)	symptom (noun)
a symptom consisting of the involuntary expulsion of air from the nose	anything that accompanies X and is regarded as an indication of X's existence
	(medicine) any sensation or change in bodily function that is experienced by a patient and is associated with a particular disease