What is the cause of black urine?

Urine black yellow, certainly not normal. This situation must be tested urine routine, observe whether there are more red blood cells in the urine. Urine black may be hematuria, hematuria in the urine of the acid-base environment, it may show this situation. Especially from the upper urinary tract bleeding, there may be because of acid-base changes, showing black urine. Also may be because of increased residual urine in the bladder, blood clots, will also show urine black phenomenon. Be sure to drink plenty of water, urinate more, and promote the discharge of hematuria. B ultrasound should be done to determine whether there is a tumor in the renal ureter bladder, whether there are stones, etc.