underarm pain

I have really bad pain under my r armpit. It radiates to my back Can you offer any suggestions?

[J T Junig, MD PhD]

You need to get it 'worked up'.  The armpit or 'axilla' contains lymph nodes that filter the fluid of the immune system-- you can get swelling in the nodes that puts pressure on nerves, as the 'brachial plexus' runs right through the same area.  There are many possible causes of pain in that area, but you want to make sure that you don't have something in a lymph node that is making it enlarge and push against the nerves-- the uncommon bad stuff would include lymphoma.  If it has only been a couple weeks I would wait it out and just take some ibuprofen for it, but if it has been going on for months, you should see a physician and have it examined.