Microscopic Hematuria

What is it?

Hematuria is the presence of blood in the urine. When it is microscopic, it means you don’t see blood in your urine, but when a lab sample is examined under a microscope, some red blood cells are detected. The clinical diagnosis of microscopic hematuria is made when there are more than 3 red blood cells per high power field on the microscopic examination. If blood can be seen in the urine and the urine is pink or red tinged, we call this “gross hematuria.”

Why does it happen?

In many cases, microscopic hematuria is a benign phenomenon, and it occurs because there is inflammation or trauma in the urinary tract, from a urinary tract infection or a kidney stone. Sometimes it happens spontaneously if you are taking a blood thinner. It is possible to have microscopic hematuria without any identifiable cause. If there is no evidence for a benign cause, a workup is recommended which involves referral to a urologist.

When you see a urologist, it is to make sure there is no tumor, stone, or other pathology in the urinary tract that is causing the blood in the urine.

If hematuria is detected in conjunction with underlying kidney disease as well as protein in the urine, referral to a medical kidney doctor, called a,”nephrologist,” is warranted.

Urologic evaluation

If blood in the urine occurs as a result of a known urinary tract infection or kidney stone, a repeat urine should be done when the acute episode resolves. If there is still microscopic hematuria, we recommend a workup with 2 tests. The first is a cystoscopy, which is a test where we look inside the bladder in the office. This involves placing an instrument that looks like a long straw into the urethra in order to directly inspect the inside of the bladder. This is done in the office and does not require general anesthesia or sedation. We give you numbing jelly in the urethra to minimize discomfort. This is the best way to visualize the inner lining of the bladder and to make sure there are no lesions inside the bladder.

The second part of the evaluation for blood in the urine involves obtaining imaging of your kidneys. Depending on your age, history, and prior imaging, we may recommend a CT scan, MRI, or ultrasound. Because it gives us information about the upper part of your urinary tract, the kidneys and the ureters (the tubes which drain the urine from the kidneys down to the bladder), we call this part of the workup, “upper tract imaging.”

In certain cases, Dr. Kumar will order special tests to evaluate the cells which are shed in the urine as well.