You're worried about telling that to your GP? I can understand. But if you tell it to a "vascular specialist" or "vascular surgeon" they'll understand what you're asking. Given that you have a clotting mutation and TOS, I think you should see one soon to get more information.

Keep in mind that surgeons aren't just for surgery. They are also for consultations in their area of expertise. I didn't really know that before all this TOS stuff.

Good luck.