<s>[INST] Hi, within the last day or so I have discovered a lump about the size of a marble underneath my chin midway towards my neck. Around the same time I have been experiencing dizzy spells that r exacerbated by sudden head movements. The chin lump doesnt really hurt and it kinda feels like a swollen lymph node. Yet I have never noticed it there before. [/INST] Hi.Thanks for your query and an elucidate history.The lump under the chin is a lymph node unless otherwise proved . You may please take a course of an antibiotic and anti-inflammatory medicine under Doctor's prescription for 5 days. Consult an ENT surgeon - he will look after both the problems.  The dizziness can be due to either a cervical spondilitis or problem due to internal ear. He will be in a position to decide the reason and ask you for investigations like X-ray or MRI of the cervical spine and mastoids. And start treatment for it. </s>