Is weird bump underneath my armpit after breast reduction normal?

The best thing in this circumstance is to get another follow up appointment with your surgeon to they can do an exam to see what is going on. What you are describing does not sound very normal but it's hard to say without more information.

Hi, Thank you for the question.
An area of firmness or hardening that you are describing may be related to swelling after surgery or possibly fat necrosis.
I suggest that you seek an in person consultation by your Plastic Surgeon to discuss your concerns and to discuss if any further work up is needed.
I hope this helps.Best regards, Dr. Karanetz
Dr. Irena KaranetzBreast Fellowship-TrainedBoard Certified Plastic Surgeon

Dear Wehores6,
I understand your concern. However, without a proper assessment, it would be difficult to determine what went wrong. It is best that you visit your plastic surgeon for further assessment or ask for a second opinion. Only after a thorough examination, you can get proper recommendations and advice.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

From your description a return visit to your surgeon is warranted. It could be residual swelling, fat necrosis, or something else. An examination of the area is needed to determine the nature of the lump.

It is not normal to have a residual lump months post breast reduction. You should either return to your operating physician, or consult a new one. Best wishes.
Dr. T

Thank you for your concern and question. I recommend that you return to your surgeon for evaluation of the area of concern. There are a variety of potential causes for this, but you need to be seen.