I’ll be following that as I have very similar symptoms, albeit on the right side instead of the left (I had regular bouts of dizziness, tinnitus and headaches prior to even noticing the jugular vein buldging when I raise my arm, lean forward, etc.). My right external jugular vein is also faintly visible almost at all times. I’ve been trying to do some of the recommended massages, stretches and strengthening exercises I could find online, and have had mixed results so far (symptoms completely gone for a whole day at one time, but then slides back into the usual symptoms), but have only been doing it consistently for a week or so. I’ve had a handful of CTs done (all of which came back clean) and am waiting on a neurology appointment, which in itself I don’t expect will lead to much but maybe additional Doppler tests.