OK, now you will get another opinion LOL, so you can choose which one you like best. BFS seems to be closely related to dysautomonia. Which is shortly a body out of balance that has some issues regulating everything correctly, but benign. A part of dysauromonia is the developmen of raynaud's like symptoms, an exaggerated vasoconstriction of blood vessels which causes fingers to go blue or even white. This can often be triggered by colder-than-usual temperatures or stress.