Yesterday, while sitting and relaxing, I became aware of a pain in my upper back on the right side, kind of under the shoulder blade. It only really hurt when I tilted my head forward towards my chest and when turning my head from left to right. I went to bed and slept fine until the early hours when the pain in my back woke me up. Whatever position I lay in, the pain was there, and the only relief came from lying on my side with a cushion between my knees. Having got up in the morning and starting to move around, the pain is much worse. I went to get dressed and the pain became so bad I had to sit down. It still hurts to move my head around, but now even sitting still I can feel the pain, almost like it is in spasm or something, and even just breathing was making it hurt. It is the same area, upper right back, but the pain now also goes down the back of my right arm. I have taken some painkillers and that has eased things a bit. Sorry for rambling, but I am just worried this has come out of the blue. Although it feels like a muscle strain, I don't remember straining my back yesterday.