Hi Im 14 and just discovered a small lump in my armpit. Its about the size of a  misquito bite but its not itchy and its sore when I lift my arm. I dont feel sick or anything. Its under my left armpit. Is it a blocked sweat gland or something worse like breast cancer?
Hi! Thank you for using Chat Doctor. First, let me assure you that you do not have breast cancer. You are too young to have it or even to think about it! Since it's a sore lump, it seems to be like an infective/reactive lymph node. This can be treated with antibiotics alone. Also, keep the area clean as it is a potential site for sweat gland obstruction and further infection. Take care and have a happy health!