I have TOS! I enjoy rock climbing and would spend far too much time obsessing over indoors grades without resting properly. This all came to a head in August 2009 when I tore my right Cocorabrachialis, the tear went across a vein. There was no pain, my arm went red hot and numb.
Several days later I noticed haematoma's blossoming up on my right chest, the doctor suggested I rest it for 10 days and resume very light curling exercises.
A day or so later my arm swelled up and my fingers turned purple, the swelling was so great I lost definition in my knuckles, wrist and elbow; my right bicep was 4 inches bigger than the left. Time for the hospital!
After several tests they found a huge blood clot in my sub-clavian vein. This is one that runs between the collar bone and first rib. I was given Warfarin and Tanziparin and told to not engage in high impact sports, not to eat Kurly Kale or drink Cranberry Juice.
Several months went by before I heard anything and continued to take the rat poison and get regular blood tests. Early last year another surgeon suggest the best course of action was to remove the first rib. This would allow more room for the vein to do it's job.
However at the first meeting the surgeon said it would not be necessary to go under the knife as my body had grown a new vein.
He suggested that this was due to the fact I had continued to use weights. I know have a small vein that is always visible snaking it's way over my collar bone. During climbing sessions the right hand side of my chest looks like a road map and my right arm pumps up much sooner than the left. Life goes on.
Today, I continue to climb and use weights and deal with the fact my arm is slightly larger than the other.
Not sure if any of the above will help, just wanted you to know you are not the only one. I consider myself lucky, a friend who also climbs has TOS. He had the rib removed and now faces the prospect of another clot in the left arm.