have any of you thought of going to an acupuncturist? sometimes doctors seem to know it all, but sometimes they don't... I would suggest alternative advice... if this problem persists and you've done all you can and your doctors STILL haven't found out... why NOT go to an acupuncturist or maybe a therapist... maybe its not really in your left side at all, but you THINK it is.. When you are stressed, tired, or worried, your body does things to make you think about something else by creating problems in your body... this is a defense mechanism created by your brain. so how about go to the gym for a whole week straight and see if that makes a difference... or what bout taking 30 mins a day just to relax and meditate (think about NOTHING!), or the jacuzzi... or going to a puppy store (adopt! don't shop!), how about the beach? I have pain in my left side too, but these kinds of problems (any problems) seem to occur when I feel stressed (and boy am I stressd!)... so try to do something that relieves your pain by making you happy. personally I don't trust doctors... they make my wallet thinner with no satisfactory answer to prove its worth.