Hematuria

MICROSCOPIC HEMATURIA

Microscopic hematuria is the presence of a small amount of red blood cells detected underneath the microscope in urine. When performing a urinalysis a "dipstick" with chemical substances embedded within reagent test pads is immersed into the urine. These test pads are constructed such that they will change color in the presence of various substances in the urine. One of these test pads changes colors when red blood cells are present in the urine. In conjunction with a "test strip" evaluation of a urine, a urinalysis often includes a look at the urine underneath the microscope with or without centrifuge spinning of the urine to concentrate the sediment.

The presence of microscopic blood in the urine can be caused by a variety of conditions including cancer of the kidney, ureter (urine tube from kidney to bladder) and bladder. Blood in the urine is also caused by urinary stone disease, trauma, benign lesions of the urinary tract, and infection. Lastly, there is a normal excretion rate of red blood cells in the urine during a 24-hour period. Occasionally, there are individuals who normally excrete more red blood cells in a 24-hour period than usually is present for the standard limits set for our urinalysis.

The kidney is an interface between our blood stream and our bladder. One fourth of the body's total blood volume passes through the kidney every minute. During its transit through the kidney the blood is "screened" to take out a variety of impurities; thus making urine. Normally, as noted above, some red blood cells do escape into the urine through the membranes that interface between blood and urine.

An evaluation of microscopic hematuria is an attempt to differentiate significant causes of blood in the urine such as cancer, stones, or infection from non-ominous causes such as characterizing those individuals who just produce more red blood cells in their urine than others, but who are without significant urinary problems.

To help differentiate the variety of causes for blood in the urine, testing is performed. Repeat urinalyses are done. As urologists, we will do the urinalysis ourselves rather than sending it out to the lab for performance.
Your urine will likely be sent off to the lab to make sure that there is no infection present in a test known as urine culture and sensitivity. X-ray testing of the kidneys will be arranged. There are a variety of types of
x-rays that image the kidneys including an IVP, CT scan, and/or
renal ultrasound. An IVP is a kidney x-ray in which contrast "dye" is injected
into a vein in your arm and a series of x-rays is taken as this contrast
"highlights" your urinary system. A CT scan is a similar test; however, instead
of taking plain x-rays of the kidney, a computerized 3600 image of the inside of your abdomen and pelvis is obtained. An ultrasound does not use radiation; but rather high intensity sound waves are used to develop echo images of the kidney. Each of these tests has its advantages and disadvantages and will be selected based on your particular clinical situation.

In addition to evaluation of the urine and x-rays, various blood tests can be obtained to make sure that your kidneys are functioning normally and that your blood is adequately coagulating (clotting). The urine itself can also be sent off for special tests looking for cancer cells; this special urine test is known as a urine cytology.

The bladder can be looked into during a procedure known as cystoscopy. Cystoscopy is performed in the office when no adjunctive x-rays are required. If adjunctive x-rays and/or biopsies are required a day surgery procedure will be arranged because of the need of x-ray equipment and anesthesia.

Which test will be ordered in a particular clinical situation will vary. Ultimately however, an ominous etiology is characterized or excluded. Hopefully you will be one of the individuals who does not have a cause which needs further medical treatment. If you are given a diagnosis which warrants
further evaluation or treatment, that will be explained. If however, after a
reasonable and prudent evaluation of possible ominous causes you show no
significant abnormalities, it will therefore be likely that you have a renal (kidney) leakage of red blood cells into your urine. If this is the case, you will be counseled to continue prudent medical evaluation on a regular basis. This would include but is not limited to measurements of your blood pressure, repeat urinalyses, and other good basic medical preventative care. We certainly and always want you to avoid the use of tobacco products, exposure to hazardous chemicals, or the ingestion of an unhealthy diet. We trust that this patient education handout is helpful in explaining what microscopic hematuria is, its possible causes, evaluation, and subsequent implications. We realize that it is sometimes alarming to have a condition which you cannot see and which may or may not be significant. It is our
hope that this information will provide you with not only an education, but a
reduction in any anxiety which you may experience. Of course, please feel free to ask questions.