1. You say mystery, I say puzzle. It is either way.
2. Pain, whether good or bad, is a teacher. It is trying to communicate to you. Know this and you have won half the battle.
3. Medicate pain too much or too often and you do run the risk of losing the message and causing damage or further damage as Anne hints at above. Before popping that pill try to figure out the message which is all apart of the know your anatomy, know your body and what it is doing and trying to tell you. You ONCE were in a state of no pain, no compression.
4. Exercise is possible and IS helpful. Again, slow and steady. Watch for signs. Know what you are doing and how it may or may not impact on your TOS. In the exercise thread given above, I mentioned my lesson with the simple bicep curl. This was so key to me for that exercise as well as others and for some day to day tasks. It became apparent because of pain. Bad pain to be specific. At the time I was learning the anatomy and it occurred to me that in "carrying a box" (think about what your upper body is doing in that position) or doing a bicep curl (same thing...look at what your upper body is doing) unless I stood up a bit straighter or tried to keep my shoulders back throughout, I'd compress the nerve as it passed under the coracoid process...why? because just the slight bend forward of the upper chest reduces that space...the carrying or the bicep curl requires the biceps...the bicep has two tendons ONE is attached to the coracoid process if you cause it to pull down on reduced space..bam..compression of the BP. Now..if I maintain the good posture, no compression...no pain...no irritation. I still have the ability to carry boxes, and do bicep curls. Same thing applies when I bend over to do anything in that position...I merely try to hold the shoulders back...instead of rounding forward to get that extra inch in the bend forward. Try it. You may understand the difference. Understand the difference and you may be able to improve your situation. Many more tasks are now available to me without flare ups and without pain IF I hold my shoulders back. It was hard to do at first because those muscles were weak hence the "default" relaxed position of tight pec minors weak rhomboids and rounded shoulders and kyphotic upper back...I worked on strengthening the back and not the pecs and I am now more easily able to hold a better posture...it is almost to a point of a default relaxed position without much effort. I still have a ways to go...but the feed back is positive in that I have less flareups and less pain and the ability to do more. I can't emphasize enough the above points. At the risk of getting flamed, if you are not getting better search your brain hard for responsibility in medicating first and not wanting to learn what the body is trying to tell you. It's not easy to accept this responsibilty and I'm not accusing anyone of being to quick to medicate or get under the knife but there are many out there. Do an honest assessment of your own situation to see if quite honestly you fall in that category. If you don't...more power to you and your efforts to get better.