Microscopic hematuria is the finding of blood on a urine dipstick or by seeing red blood cells in the urine under microscopic magnification. Often, women with microscopic hematuria have no symptoms but their doctor finds blood on a routine urinalysis. A patient with microscopic hematuria can not see the blood in their urine with the naked eye. A patient who sees blood in their urine should contact their doctor as soon as possible.
A patient with microscopic hematuria may have something in their history that helps determine why they have blood in their urine. These include a recent or current urinary tract infection, a recent upper respiratory tract infection, a family history of kidney disease, flank pain (possible kidney stones), menstruation, trauma, recent travel, and certain medications.
Oftentimes, we are unable to determine the exact cause for microscopic hematuria.
A dipstick urinalysis is very sensitive for detecting blood in the urine so this can result in a high rate of false-positive tests–meaning although the urinalysis shows blood, if we examine the urine under a microscope we may not see any red blood cells. The first step is to send the urine for microscopic urinalysis and confirm there are at least 3 or more red blood cells seen per high power field. If so, then we proceed with a full evaluation. A full evaluation usually includes blood work to evaluate kidney function, a cystoscopy whereby we use a camera to look inside the bladder, and finally a CT scan of the abdomen and pelvis or a renal (kidney) ultrasound.
Treatment of microscopic hematuria is based on the underlying etiology. If a patient is found to have a urinary tract infection, this can be treated with antibiotics. Kidney stones can be treated or removed if needed. If a tumor or growth is found in the urinary tract, this can be removed. Treatment of any underlying kidney disease can be initiated.
Again, many times a workup does not identify a cause, in which case treatment may not be necessary but the patient may need monitoring or repeat evaluation in the future.