Blood in the urine, or hematuria, is a common complaint amongst patients who are seen in a Urology office. It is fairly dramatic for the patient when they urinate and see a toilet filled with blood. Blood in the urine may also not be that subtle, and may only be noticed by the physician when they perform a urinalysis. This type of bleeding is known as microscopic hematuria.
The evaluation of gross bleeding is fairly straightforward - It requires several different tests that evaluate various parts of the urinary tract:
A urinary cytology is performed. During this test a urine sample is evaluated for abnormal cells that may be contributing to the bleeding.
An imaging study, a CT scan should be performed. This test should ideally be performed with intravenous contrast. It evaluates the kidneys, the ureters and the bladder.
Lastly a cystoscopic evaluation needs to be completed. Cystoscopy involves placing a scope into the urethra and allowing for the evaluation of the lining of the bladder, as well as the urethra and the prostate in men. If the bleeding is coming from the kidneys, this will allow for the localization of the problem to one of the kidneys as the blood may be seen emanating from one of the orifices, the openings from the kidney into the bladder.
The evaluation of microscopic blood is more controversial. First, it is very important to define what constitutes microscopic hematuria. The American Urological Guidelines for microscopic blood without symptoms defines it as three or greater red blood cells per high powered field in a properly collected specimen without an obvious benign cause. Many times patients are told they have microscopic hematuria on the basis of a dipstick being positive, however, this does not define microscopic hematuria and this alone should not lead to one undergoing evaluation.
After benign causes such as infection, menses, or recent trauma are excluded, an evaluation should be undertaken. It is also important to exclude intrinsic diseases of the kidneys as a source of the bleeding. Cystoscopic evaluation may be considered in these patients, especially if they have risk factors for malignancy such as smoking. Imaging studies and cytology should also be performed. Many of these patients may have persistent microscopic blood, however if these patients were to go a period of 2 years without a positive urinalysis, ongoing evaluation should not be performed. After an initial negative evaluation, the AUA states that an additional evaluation should be conideredere within three to five years.
A recent study from the University of Pennsylvania assessed the management of patients with microscopic hematuria by primary care providers. Most physicians were unable to provide the correct definition of the entity. Interestingly less than half surveyed would appropriately recommend urological evaluation.
_If you suddenly see blood in the urine, make sure that you see a Urologist as quickly as possible, because the vast amount of gross bleeding is associated with a severe underlying condition. If you are told that you have microscopic blood, speak to your doctor so that you and your provided have a complete understanding of the entity, and why you may need to undergo specific testing. _