Hematuria is the presence of abnormal amounts of red blood cells in the urine that can be identified by microscopic exam and/or visually, when there are significant amounts the urine is usually red.

A chemical dipstick is very sensitive for red cells, in the urine, and can be used easily at the time of general physical exam to determine if there is blood in the urine. Blood in the urine is either from the kidney tissue itself or the collecting system of the urinary tract. The reason the difference is important is that when it is from the kidney itself, it can be associated with either a tumor of the kidney tissue, called a renal cell cancer, or a variety of inflammatory conditions, in the kidney, the most common referred to as glamerleonephritis. When blood is from the collecting system of the kidney, or the uereter, or bladder, it usually arises either from injury to the lining , such as might  as occur with a stone passing, or a tumor growth in the lining, which is known as transitional cell carcinoma. These can make up tumors of the renal pelvis, ureter, or bladder.

Benign hematuria is frequently found, this can effect children or adults ,and essentially means that blood is leaking through the filter that the kidney really makes up, but not because of a specific disease or injury ,but rather that under normal circumstances in many people small amounts of blood cells do escape through the koch kidneys' filtering mechanism and then appear in the blood either under the microscope or on a chemical dipstick. The problem is that many times this finding will lead a doctor to conclude that there is a much more serious problem and because of this concern extensive urologic evaluation is frequently done. This evaluation includes serial examinations of the urine to make sure that the red cells are frequent or reproducible findings, also a check to see if there  are significant amounts of protein in the urine. Diagnostic imaging studies, such as an Intravenous Pylegram (IVP),will be ordered  and this gives an X-ray picture of the kidney, the renal pelvis, the ureter and the urinary bladder. If there is an abnormality of the image then further studies may be ordered to better understand it, however, in some circumstances the image will be normal. When blood cells are present and the X-ray image of the urinary tract , done with the IVP, is normal than other studies are required to look at the lower urinary tract, this includes cystoscopy which is a flexible optical scope that can be passed through the urethra to examine the urethra, in men the prostate and the bladder  in either men or women. Abnormal findings in these areas can include tumors of the lining of either the urethra or the bladder, stones, or evidence of inflammation and infection. In men sometimes problems with the prostate such as inflammation or cancer of the prostate can produce blood in the urine.

Hematuria then is an early warning sign that urologists use to understand the health of the urinary tract. The finding of blood cells in the urine as can be seen from the previous information can lead to an extensive evaluation of the urinary tract and the diagnosis of very significant conditions such as kidney stones, stones in the ureter or bladder, tumor of either the kidney or lining of the cells of the collecting system, which includes the kidney pelvis, ureter, bladder or urethra ( the tube that leads from the bladder to the outside) and in some instances can lead to the diagnosis of a cancer of the prostate.

If a person sees blood in their urine they should contact their urologists right away to be seen and evaluated, if a urologist is not known to the patient, he/she should consult their family doctor.