Lump under arm

[Kermit7]

I have recently developed a rash under my right arm.  I had assumed it was because of either shaving or the deoderant but I have a lump about the size of an english pea.  This area is kinda tender.  Is this something that I should be worried about.  I will be 35 in May.  The rash is just about gone but the lump is still there.

[the angel]

MY SISTER-IN-LAW HAS RECENTLY FOUND A LUMP UNDER HER ARM, I TOLD HER TO GO TO THE DOCTORS BUT SHE STILL HASNT BEEN, SHE SAYS THE LUMP IS SORE AND IT CAN MOVE, I DONT KNOW WHAT TO TELL HER BECAUSE IS THERE ANYONE WHO MIGHT HAVE ANY IDEA WHAT IT COULD BE.

[the angel]

MY SISTER-IN-LAW HAS RECENTLY FOUND A LUMP UNDER HER ARM, I TOLD HER TO GO TO THE DOCTORS BUT SHE STILL HASNT BEEN, SHE SAYS THE LUMP IS SORE AND IT CAN MOVE, I DONT KNOW WHAT TO TELL HER BECAUSE IS THERE ANYONE WHO MIGHT HAVE ANY IDEA WHAT IT COULD BE.

[brendam]

Hi,
Could you please advise.
3 weeks ago I noticed a small lump under my arm-it has doubled in size over the past 3 weeks and is quite tender.
Your thoughts on what this might be are appreciated.

[CCF-RN,MSN-JS]

Dear Kermit7, There can be a number of non-cancerous causes to what you are feeling.  For instance, it could be an ingrown hair that has caused some swelling, or you may be feeling a lymph node.  However, if this does not resolve itself or worsens you may want to get it checked out.