An irritating lump under the arm.

[TSJones]

Yesterday on my way home from school I felt this slight pain under my arm, so I shifted my arm so that the pain would go away. After the bus ride I went inside and felt the pain again upon shifting my arm. So I reached under my arm to find a bump about the size of the head of a Q-tip. I had no idea what it was. Looking around on the internet I found that it could be one of many things. Apparently there are lymph nodes under your arm that swell as they fight infection. My main fear is that it could be cancer. I've never shaved my arm pits. However I think its come as a result of me using deoderant that had the top off for about a day. It was kinda hard but I still used it. Im wondering if maybe I rubbed a hair outta place and its trying to grow in? It doesnt look the way those bumps do when someone shaves against their hair. I think thats about everything.. I showed my dad a few hours ago and he said it was a zit/pimple and that the only thing to do was to wait for it to pop. After doing more research Im seriously beginning to doubt its a zit/pimple. Im 18 years old and Ive checked for bumps in other reasons and found nothing. Ive checked my "breasts" my other arm pit and groin and theres nothing out of the normal. Should I just wait and see what happens with this?

[J.M. Keyes, MD]

It is difficult to give you a good idea of what it is without examining you, but you are right in that it is most likely a pimple/blocked hair duct, or an inflamed lymph node that has become enlarged because it is trying to fight some infection.  The infection doesn't necessarily have to be in the armpit- it can be further down the arm, so check to see if you have a cut or scratch elsewhere in that arm.  An infection can worsen to the point that it needs further treatment, so if it is becoming red, warm to touch, and/or more painful, see your doctor.

It is very unlikely that this is cancer.  Malignant lumps are usually not actually tender, so the fact that yours is sore makes it more likely that it is do to the causes above.  Malignant lumps also tend to be hard, and fixed (ie- they won't move back and forth between your fingers).  Also, with cancer, you will often have associated symptoms like weight loss, night sweats, or fevers.  If you are having anything like this, or if this lump is getting bigger, or not going away in the next couple of weeks, be sure to see your doctor.

There are also benign (not cancer) lumps, like "lipomas"- a collection of fat cells, but again, this is less likely because it is sore.

In the meantime, try not to pick at it- this can make it worse.  Use warm compresses a few times a day.  Take something for pain- ibuprofen helps with pain and is an anti-inflammatory.  Keep an eye on it, but try not to spend time worrying about it.  Just be sure to follow up with your doctor if it's getting worse, not going away, or you are having other symptoms you are worried about.

Good luck and feel better.
JMK MD

[J.M. Keyes, MD]

Thank you for the feedback.  I'm glad I could help.

JMK MD

[TSJones]

Thank you doctor. Your answer really put my mind at ease. I did what you suggested and used a few warm compresses and left the bump alone otherwise. Im just waking up here to notice that the bump has gotten smaller. I can finally rest easy, you have my thanks.