Brief Answer:
Please provide more information

Detailed Answer:
Hello
I had gone through your question very diligently and I will help you out in best possible way.

Looking at your description it seems to a treatable condition so you need not to worry
This might be related to infection of parotid gland or inflammation of lymph gland.

Here, I would like further information to help you better as
Since how long you have upper respiratory infection
What all treatment you have taken for it
can you feel the lump, is it having well defined margins or diffuse lump
Is it hard to touch or soft cystic swelling
can you feel any kind of pulsation in it.
Are you running fever?

This lump might not be related.to carotid artery or anything serous issues.

Please write back to me with these details so that I will be able to tell you more accurately
Best wishes

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Brief Answer:
Wait and observe for next 2 to 3 days

Detailed Answer:
Hello,

Based on your description, the location of the lump doesn't seem to be related to carotid artery.
Since it has appeared overnight most likely it could be a benign condition and not likely to be a serious issue. I would not be worried about it yet.

In my opinion you should wait and observe it for next 2 to 3 days. If it increases in size or consistency and appearance changes then you should visit a nearest doctor and get it checked. You might need an ultrasound scan.

Thanks for your question

Best wishes

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