Thanks for writing to us.
A swollen gland under the jaw is most likely a swollen neck lymph
node. It commonly occurs due to any infection in the head and neck region commonly due to a dental infection. The other causes can be chronic infections, metabolic disorders, malignancies, viral illnesses, etc. All these causes can be ruled out by having an FNAC of the gland under the guidance of your physician.
I hope this information has been both informative and helpful for you.
Dr. Praveen Tayal