Hematuria is defined as blood in the urine.
There may be blood in the urine with almost any kidney or bladder problem. It can be caused by urinary tract infections, urinary stones, injury, cancer in the urinary tract, structural abnormalities, or diseases of the kidney. Hematuria may be an early warning sign for serious medical conditions. Hematuria may or may not be painful, depending on its cause. Other symptoms that could be associated with hematuria are abdominal pain, flank pain, burning with urination, or the frequent urge to urinate.