Have middle back pain on the right side off on 3 months had urine test adomin x ray and blood test what could it be?

Ongoing trial: You may wish to evaluate your activities during the day. Are you straining your back in some of the activities? Carrying a child in your arms? Are you driving long distance to/from your work? It might be a good time to try some stretching activities if the first step bloodwork looked ok. Obviously, if issues persist, a second look as to what could be the source of this pain is required.