palpitation vs symptom

palpitation and symptom both are nouns.

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

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

palpitation: a rapid and irregular heart beat
symptom: (medicine) any sensation or change in bodily function that is experienced by a patient and is associated with a particular disease

palpitation (noun)	symptom (noun)
a rapid and irregular heart beat	anything that accompanies X and is regarded as an indication of X's existence
a shaky motion	(medicine) any sensation or change in bodily function that is experienced by a patient and is associated with a particular disease