I have a hard ish lymph node popped up in side of neck not far under jaw. Are nodes of concern or can they be raised in reaction to ulcers etc?

X

Typically painful nodes are related to some infection. Non painful swollen nodes can be related to cancer. Either way if this node(s) doesn't resolve itself within a couple of weeks get an appt with an ENT.

Ditto what David said - nodes are reactive to many things - inflammation, infection, illness - however if it doesn't go away in a reasonable amount if time you need to be checked. Hugs