A few months ago i started taking medication for my thyroid condition (I have hypothyroid). I dont know if it is related, but it was only a few months after that I wake up with the feeling of pain under my left arm pit. I feel that my left breast has slightly grown bigger. I have been done three ultrasounds which confirmt that it is only a matter of tissues but they are benign. I am just curious why i still this one small area under my armpit that is painful when you touch it. The rest of the breast seems fine to me. Any advice what i could do?