When I have my right arm hanging down normally, like when I’m standing, it gets blue, like the blood cuts off and it’s painful. It doesn’t feel numb and I don’t get pins and needles. This happens until I raise my arm up, then the blood comes back to it and the color goes back to normal. I had X-rays done a few years ago and they didn’t show anything out of the ordinary. What could this be? What kind of doctor should I see for it?