I have this back pain that is in the upper to middle part of my back. and it keeps on coming back. do you happen to know what cause this?

Back pain : I have seen thousands of people with spinal pain. I can't tell you how important an in-person examination is needed to help you. Things to consider is that you may have an abnormal curve such as scoliosis or a relative (unlikely real) leg length differences contributing to the pain. The back can be affected by poor foot aches, knee or hip issues or problems with the alignment of the pelvis or leg