<s>[INST] My 15 year old son experiences pain in the upper left abdomen just below the rib cage when swallowing while eating. He also had a small round knot on the left side of this neck which was sore to the touch for several days. The knot has gone down today, He has complained with occasional dizziness and headaches . Didn t know I would have to pay $18.00 for an answer. [/INST] Hi welcome to Chat Doctor forum.  Thanks for choosing Chat Doctor. Forum.  Your 15 years son had left upper abdominal pain, while swallowing. There was a knot on the left side of his neck which was sore to touch, that has come down today. He is also complaining of dizziness and headache.  It appears to be the T.B.gland (maybe) as it has changed in position and structure, and probably caused pressure on the esophagus, and causing pain. Or it may be gastric irritation, or pancreatitis pain.  It is our assumption only, I advise you to consult a gastroenterologist for diagnosis and treatment. You may have to get the M.R.I. gastrostomy besides other routine tests for confirmation.  Wishing for a quick and complete recovery.  Best regards. </s>