My doctor said i have a small goiter what does that mean? also i have hypothyroidism.

Maybe nothing : A goiter can either be functional or non- functional. A lot of goiters are non functional and do no harm at all unless they get so big and begin to compress your airway. The functional ones are the ones we are a but more concerned about and usually it is because they secrete too much hormone to your blood. If your doctor said it was small then most likely it's fine.