How is blood in urine diagnosed?

The evaluation for blood in urine consists of taking a history, performing a physical examination, evaluating the urine under a microscope, and obtaining a culture of the urine. A significant history would include whether or not there was any pain or discomfort associated with the hematuria, whether the blood was present in the beginning, end, or throughout the urinary stream, and finally, whether there is a personal history of smoking, kidney stones, injuries to the urinary tract, trouble urinating, or previous urologic evaluation.

No matter how obvious the reason for hematuria appears to be, a complete evaluation is almost always necessary to rule out a serious underlying disease, such as a cancer. There are usually three diagnostic tests necessary to give us a look at the entire urinary tract, and these include a computed tomography (CT) scan of the abdomen and pelvis, cystoscopy, and a urine cytology.

The CT scan is an imaging evaluation of the urinary tract. Prior to the procedure, the patient drinks an oral contrast agent, and a dye is injected intravenously. The patient then goes through the CT scan machine and images are taken of the abdomen and pelvis. Another test that can be performed, the intravenous pyelogram (IVP), is also a type of X-ray evaluation of the urinary tract. In this procedure, a dye is injected into the veins, and this is filtered by the urinary tract. A series of X-rays are then taken over a 30-minute period, looking for abnormalities. The CT scan is more commonly performed than the IVP to evaluate the urinary tract and should be considered the test of choice. Both of these studies are especially useful for evaluating the kidneys and ureters but not the bladder, prostate, or urethra. Therefore, a second examination called a cystoscopy is necessary. In this procedure, a cystoscope (thin fiberoptic camera) is used to visually inspect the bladder and the urethra. In most instances, this can be done without discomfort by the use of local anesthetic jelly. The cystoscope is passed up the urethra into the bladder, and the inspection is carried out. The entire examination takes less than 10 minutes. The final test is a urine cytology, which involves voiding urine into a cup and having that urine examined by a pathologist to look for cancer cells.