Hematuria is a condition where blood is present in the urine. Gross hematuria refers to visible blood in the urine.
Microscopic hematuria describes blood in the urine that is only detected through a urine test called urinalysis. Microscopic hematuria is diagnosed if there are three or more red blood cells present when urine is viewed under a microscope.
Causes and Risk Factors
There are several non-cancerous causes of hematuria including infection, vigorous exercise, medical renal disease, recent instrumentation, inflammation, and kidney stones. Further evaluation is typically required however because hematuria may indicate the presence of an underlying cancer (approximately 23% risk for gross hematuria and approximately 3% risk for microscopic hematuria). This evaluation is necessary even in the setting of anticoagulation.
When to Speak with a Urologist about Hematuria
You should speak to a Urologist about hematuria if you notice red or pink urine or if you have been told by another physician that there is microscopic blood in your urine.
What to Expect when Seeking Treatment
In addition to a history and physical examination, the initial evaluation includes a formal urinalysis with urine culture as indicated to determine presence of underlying infection. Blood testing will include as assessment of kidney function to test if your kidneys are healthy enough to undergo imaging with contrast. To identify pathologies in the kidney and ureter, a specialized CT scan called a CT urogram is obtained. Cystoscopy, where a small flexible camera is passed up the urethra into the bladder, is necessary to evaluate the bladder lining. If risk factors for cancer are present, such as smoking and pelvic radiation, a voided urine cytology is sometimes used to assess for underlying high-grade malignancy by examining the cells in the urine.
Treatment options vary depending on the underlying cause of hematuria. For example, if no abnormalities are identified, no specific treatment is necessary. Other treatments may include antibiotics for infection, removal of kidney stones, or biopsy for a suspicious area found in the bladder.
In general, patients with visible blood in their urine should drink plenty of fluids to dilute the urine and to hold blood thinning and anti-platelet agents unless required by their cardiologist.
Rarely, blood clots in the bladder during gross hematuria may impair the ability to empty by causing blockage leading to urinary retention. The symptoms of urinary retention include a sensation of fullness that continues to increase and become painful in the absence of ability to pass urine. If concerned for urinary retention, immediate medical attention is necessary for possible catheter placement.
In the event of identification of a benign cause, or when no cause is found, a follow-up formal urinalysis is required to confirm resolution. Annual formal urinalysis is needed for 3 years, or until two consecutive negative formal urinalyses are obtained. In the setting of persistent hematuria following negative work-up, patients may be referred to nephrology to consider a cause within the kidney itself, and sometimes a repeat work-up is warranted.