What Makes The Neck Distended When The Arm Rises Causing Difficulty In Breathing?

When I raise my arms high, or even pull my arms back hard and a bit up, the veins in my neck begin to distend some. I have no other pemberton sign symptoms such as flushing that I can see, nor stridor. I have had some difficulty breathing for a year and a half, but nothing serious and it hasn t changed. I ve had two CT scans of the lungs b/c of a dimer test (checking for clots, then found a nodule, so there was a follow up CT). Nevertheless, does the increased pressure in the vessels mean anything or is this kind of thing normal?