Does anyone know what could cause pain in your chest that shoots under your armpit. This pain is felt under my left breast and feels like someone is pinching me really hard. I had a stress test at the ER last week and just recently had an echo(awaiting results ). I am also having my feet swell (just given a perscription for that). I saw my cardiologist and asked him if it could be a nerve related and he said that there is no test for nerves on the chest wall, just the upper part of the body and if it was nerve there is nothing that can be done. I just like to know what is causing it. It comes on when I am doing things and last about a min and half. I just get tired of looking stupid if you know what I mean.