A painful, raised lump appeared on my left underarm earlier today that I am concerned about. I am planning on having it looked at by a doctor, but I was hoping for some immediate opinions. I am a 22-year-old, otherwise healthy female. I have no history of serious illness and I'm not taking any medications.
There are a few things I thought of when the lump appeared that may or may not be related:
I have had a lesion (on the same side as the underarm lump) removed from my left shoulder two years ago by a dermatologist, however that was relatively minor. Also, I just started my period today (and the lump appeared today). Could it be that hormones caused the lump? Though that does not explain why a lump would appear now, all of a sudden. In addition, I've been to a doctor in the past year because I had some unusual breast pain (that his since gone away). There was an ultrasound done, but no problems were found.
I have no clue what might be causing it. I have read that it could be a number of things. Any insight on this would be appreciated.