I have been told "the brain seeks symmetry" by my Feldenkreis PT. If you continue to have chronic problems on one side, eventually they 'could' start on the opposite side as a result of the brain trying to equalize things.

I imagine it could be likewise with the legs (upper body always hurts - the brain causes the legs issues?), but if I were you, I'd check out the possibility of arterial blockage in the legs, low spine problems, or some other problem.

Many people with TOS have additional dx.