<s>[INST] I have a hard lump behind my right ear on my neck.  It is painless, immovable and doesn't appear to be inflamed but has been present for months.  I haven't noticed any symptoms like pain, fatigue, headache, etc.  The only thing I have noticed is that I have been slightly dizzy on a couple of occasions.  I have many allergies and take medication for hypothyroidism.  Could this be something simple like allergies or should I be more concerned? [/INST] Hi.This lump is most likely to be a lymph node. The simplest way to confirm by ultrasonography and FNAC.This helps the exact diagnosis and can guide the treatment. Dizziness or allergy may not have to do anything with  it . Looking at the site of it , it is better to worry about it. </s>