Pain in my lower back on the right side.

Doctor can examine: Doctor can get the details and do an exam. Back pain on either side of the spine (called flank pain by doctors) can be caused by kidney disease, especially if the person doesn't remember hurting his back by lifting or working too much. Other abdominal problems (occasionally serious ones such as a tumor) can also show up as back pain, as can spine, nerve, or back muscle problems.