What is the cause of a swollen lymph node under my chin? It is not painful, however, sometimes it gets aggravated by swallowing. Is this worrisome?

Probably not. Lymph nodes enlarge in response to inflammation since they are designed to help fight this. The oral cavity is a major source of minor inflammation/infection and a swollen lymph node is not surprising. If it remains small, is soft and non-tender, and you have no other symptoms it should resolve. If not, have it seen by your family doctor or an ent.
Salivary gland. Could this be a salivary gland the is worsening when eating and swallowing , lymph node should not be painful with simply swallowing.

Related Questions

I've had a swollen lymph node under my chin for 3 months. My doc told me not to worry but I'm scared. Is it really ok for it to be swollen this long?

Maybe. Without being able to feel this node it is difficult to say, but if it is soft, movable (not fixed to underlying tissue), not particularly tender, hot or red, then there is a high likelihood that it is entirely benign. It is possible that it is enlarged because you have a persistent focus of inflammation in the area (dental or gum problem, etc.). This is a common area for enlarged nodes. Read more...

I have a very swollen lymph node under my chin that presented two days ago. I'm not sick, and this happens once every few months. Should I be worried?

Lymphadenpathy. This node sounds like it is doing what it is supposed to do. Fighting inflammation. You may have a dental issue, a low grade inflammation in the area, trauma, and so on. Would not worry unless this becomes permanent, hard to the touch, and fixed to underlying tissue or it is becoming progressively larger. Good luck. Read more...