Hematuria

What is blood in urine (hematuria)?

Hematuria, or blood in the urine, can be either gross (visible) or microscopic (as defined by more than three to five red blood cells per high power field when viewed under magnification). Gross hematuria can vary widely in appearance, from light pink to deep red with clots. Despite the quantity of blood in the urine being different, the types of conditions that can cause the problem are the same, and the workup or evaluation that is needed is identical.

People with gross hematuria usually present to their doctor with this as a primary complaint. Microscopic hematuria, on the other hand, is most commonly detected as part of a periodic checkup by a primary-care physician.

What are the causes of blood in urine?

The causes of gross and microscopic hematuria are similar and may result from bleeding anywhere along the urinary tract. One cannot readily distinguish between blood originating in the kidneys, ureters (the tubes that transport urine from the kidneys to the bladder), bladder, or urethra. Any degree of blood in the urine should be fully evaluated by a physician, even if it resolves spontaneously.

Infection of the urine, stemming either from the kidneys or bladder, is a common cause of microscopic hematuria. Kidney and bladder stones can cause irritation and abrasion of the urinary tract, leading to microscopic or gross hematuria. Trauma affecting any of the components of the urinary tract or the prostate can lead to bloody urine. Hematuria can also be associated with renal (or kidney) disease, as well as hematologic disorders involving the body's clotting system. Medications that increase the risk of bleeding, such as aspirin, warfarin (Coumadin), or clopidogrel (Plavix), may also lead to bloody urine. Lastly, cancer anywhere along the urinary tract can present with hematuria.

How is blood in urine diagnosed?

The evaluation for blood in urine consists of taking a history, performing a physical examination, evaluating the urine under a microscope, and obtaining a culture of the urine. Lower urinary tract symptoms, such as urgency (feeling a strong need to urinate) and frequency (needing to urinate frequently), as well as the presence of fever and/or chills are suggestive of infection. Recent trauma, even if believed by the patient to have been inconsequential, should be considered as a potential cause. Abdominal and/or flank pain, especially if radiating to the inguinal or the genital area, may suggest kidney stones. All recent medications, including vitamins or herbal supplements, should be reviewed with the health-care provider. However, it is important to note that even if the patient has been taking a medication that is associated with bleeding, a full workup (as listed below) should still be undertaken.

The physical exam will focus on possible sources of hematuria. Bruising over the back or abdomen may indicate trauma. A digital rectal exam should be performed, as findings consistent with prostatitis (for example, tenderness on palpation of the prostate) or an enlarged prostate (suggestive of BPH or benign enlargement of the prostate gland) may be useful in making a diagnosis. A repeat urinalysis, as well as a urine culture, should be obtained. The presence of white blood cells on urinalysis is more consistent with a urinary tract infection. Protein, glucose, or sediment in the urine may indicate the presence of a disease of the kidneys. Blood tests are also important, as they will aid in assessing renal function and identifying any clotting abnormalities.

In addition to the basic history and physical exam, there are three additional components for any workup of hematuria: CT scan, urine cytology, and cystoscopy.

The CT scan is an imaging evaluation of the urinary tract. Prior to the procedure, the patient drinks an oral contrast agent and a dye is injected intravenously. The patient then goes through the CT scan machine and images are taken of the abdomen and pelvis. Another test that can be performed, the intravenous pyelogram (IVP), is also a type of X-ray evaluation of the urinary tract. In this procedure, a dye is injected into the veins, and this is filtered by the urinary tract. A series of X-rays are then taken over a 30-minute period to look for abnormalities. The CT scan is more commonly performed than the IVP to evaluate the urinary tract and should be considered the test of choice. Both of these studies are especially useful for evaluating the kidneys and ureters but not the bladder, prostate, or urethra. Therefore, a second examination called a cystoscopy is necessary. This is a simple 10-minute procedure wherein a thin, flexible cystoscope (or fiberoptic camera) is inserted via the urethra into the bladder in order to directly visualize any lesions or sources of bleeding. This is usually done with local anesthetic jelly injected into the urethra. Finally, urine cytology involves giving a urine sample to be analyzed by a pathologist for the presence of cancerous or abnormal-appearing cells.

How is blood in urine treated?

Treatments for hematuria vary widely and depend wholly upon the reason for the bleeding. It is important to note that there is often no source found for the hematuria. This should not be a source of major concern, however, since an appropriate workup effectively rules out the most serious causes of hematuria (for example, cancer). In cases where a workup is negative and the cause of the hematuria remains unknown, observation with repeat urinalyses is a reasonable option. A blood test to check kidney function and a blood-pressure check should be done as well. Men over 50 should discuss with their doctor the yearly prostate-specific antigen (PSA) blood test to screen for prostate cancer.

Further discussion of the treatment for hematuria would depend upon the results of the previously mentioned workup and the exact cause for the hematuria. The urologist who performs this examination would direct any further treatment or workup that would be necessary.

Blood in Urine (Hematuria) At A Glance

• Blood in urine can sometimes be visible only with a microscope.
• Evaluating blood in urine requires consideration of the entire urinary tract.
• Tests used for the diagnosis of blood in urine include a CT scan, cystoscopy, and urine cytology.
• Management of blood in the urine depends upon the underlying cause.