Hello, The kidney issues may not have symptoms at all, or if there is problem in kidney function some times there can be swelling in legs or face, and / or frothing in urine. Most of them you will know only when you test blood for creatinine or do an urine test for protein. The pain on the site of the kidney can be due to stone which can be confirmed by an ultrasound scan. If all the above are normal your pain is likely originating from the spine or muscles. If you have a dark black urine, then it is something more serious. It is seen when blood cells or muscles get damaged. You have to check blood hemoglobin, creatine kinase, and potassium and further tests will follow that. Is the dark black (you have mentioned) for the stools? If so it has to verified by a stool occult blood test, and then further evaluated by gastroenterology. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Praseetha Narayanan, OB & GYN Specialist