@dream1649 Janet, that's a good question, and I probably should be using a better pillow. I also have thoracic outlet syndrome and when I lay on my side it compresses my shoulder and causes arm pain. If my head is not in line with my spine because of being above or below it, that is side bending my neck a bit and it will cause pain and aggravate the shoulder too. What I've been doing is stack pillows under my ribs and under my head leaving a slot for my arm and shoulder to take the pressure off while keeping things in line. I started using a bed wedge for this because it helps with acid reflux when you lay down. I make adjustments and still even end up rolling a pillow under my head sometimes. I used to have a firm foam pillow that helped keep my head level and probably need to get another one.
Jennifer