sx is short for symptoms
dx -diagnosis
hx- history

If it is TOS plus some c/6 pain - be careful of general PT type of therapy - many have had a bad PT experiences because they start the strengthening /weights way to soon for the TOS.
With TOS we tend to get delayed pain/flare ups like a day or 2 after the use that caused the flare.
you might ask drs for copies of your appt records so you can be sure of what was said and dx'd.
many of us have some brain fog too.

many drs don't have in depth knowledge about TOS at all- none of mine even mentioned it or thought my sx weren't "bad" enough to be it.

But they never saw me at the worst times because I had found my good chiro at that time and he did help resolve many sx and then also an expert PT that did mobilize{drop} my stuck and raised top ribs.{from the severe spasms}