Pain in the lower left back could indicate a problem with the muscles, joints, mid-back, or organs in the pelvic area. Common sources of pain include muscle injuries, kidney problems, and arthritis.

Pain in the back, belly, or side Kidney stone pain — also ... right away if you have the following symptoms, which could indicate that you have an infection or other serious complication ...

Common causes of pain on the left side of the body ... attention as soon as possible if they have symptoms of the following: a kidney infection testicular torsion diverticulitis injured spleen ...

Cystitis, a localized bladder infection occurring in the lower tract, is recognized by a symptom complex of dysuria ... classically manifests with flank pain and systemic as well as cystitis ...