Hello,
Thank you for posting a question.

Pea sized lump on or on the side of left carotid artery indicates presence of a lymph node in the cervical region.
A lymph node in that particular site may be due to either an infectious or non infectious cause.
If you have an oral ulceration, tooth infection, then it is a quite common finding.

If you do not have any of the abovementioned conditions, then you should be clinically examined thoroughly for specific position of the lymph node, number of the nodes present, bilateral or unilateral, mobility, consistency of the nodes ( firm or hard). All of these will lead to a specific diagnosis.

In our clinical experience, most of the cases are due to reactive lymphoid hyperplasia due to an infectious condition. Keeping your age in mind we cannot take it casually. Because, sometimes some neoplastic conditions may also present with this type of lymph node.

If clinical examination does not reveal any definite cause of enlarged lymph nodes, Fine needle aspiration cytology should be carried out on the lymph node. It will reveal what is going on.

So, the lump could be a lymph node. Consult with an Ear Nose throat specialist for clinical examination, ordering a FNAC if required and for further management.

Hope this information suffices. Let me know if you have any more question.

Regards.

---