Urine is black a few days before a little back pain, indicating that there may be upper urinary tract bleeding phenomenon, may be triggered by urinary tract tumors or stones. Urine black may be caused by bleeding, if the lower urinary tract bleeding color is generally bright red, upper urinary tract bleeding, blood stasis may present the phenomenon of black urine, the patient can first through the urine routine to determine whether there is the presence of red blood cells, and the patient appeared to the phenomenon of low back pain, kidney or ureteral problems are greater, you can first urinary system CT and other tests to further determine. If the urine is black and there are symptoms of back pain, it means that the bleeding symptoms are more serious, which may be due to urinary system tumors or urinary system stones and the symptoms. It is recommended that the patient should go to the hospital in time for urinary system CT, ultrasound and other examinations to further determine the cause of the disease and then systematic treatment.