Filed Under Physician & Health Articles
Hematuria, or red blood cells in the urine, can present microscopically or grossly as visible discoloration. In either case, hematuria is abnormal, except in young females with urinary tract infections. Bleeding originates from anywhere along the urinary tract, including the kidneys, ureters, bladder, prostate, and urethra.
Blood in the urine is often not a sign of serious disease, but hematuria is sometimes a marker for infection, stone disease, urinary tract cancer, or bladder cancer. Viral infections of the urinary tract and sexually transmitted diseases, especially in women, may also cause hematuria.
Signs and Symptoms
Symptoms include abdominal pain; decreased force of urination, hesitance, or incomplete voiding; fever; frequent and/or painful urination; pain in the flank or side; and urinary urgency. Asymptomatic microscopic hematuria has many causes, including life-threatening lesions.
In women, urethral and vaginal examinations will rule out local causes of microscopic hematuria. A catheterized urinary specimen is indicated if a clean-catch specimen is unobtainable. In uncircumcised men, the foreskin should be retracted to expose the glans penis. If a phimosis is present, a catheterized urinary specimen may be required.
In gross hematuria, the urine is red, pink, or dark brown and may contain small blood clots. However, the amount of blood in the urine is not a reliable indicator of the patient’s condition. Reddish urine not caused by bleeding (pseudohematuria) can be caused by excessive consumption of certain foods or medications. “Jogger’s hematuria” results from minor bladder hemorrhaging during running.
Diagnosing the Condition
In microscopic hematuria, the amount of blood in the urine is so small that it can only be detected by microscope. The American Urological Association’s definition of microscopic hematuria is three or more red blood cells per high-power field on microscopic evaluation of urinary sediment from two or three urinalysis specimens.
When hematuria is suspected, a midstream urine sample is applied to a chemically treated strip to see if it changes color, indicating blood in the urine. A positive result necessitates further examination.
Laboratory analysis includes urinalysis and microscopic examination of urinary sediment. The urine is examined for protein — an indication of kidney disease — and any evidence of urinary tract infection. The number of red blood cells per high-powered field is determined and the shape of the blood cells are evaluated to determine the origin of the bleeding.
The point when bleeding occurs during urination may indicate the location of the discharge. Initial hematuria at the onset of urination points to the urethra or prostate in men. Total hematuria throughout urination may originate from the bladder, ureter, or kidneys. Terminal hematuria at the end of urination points to the bladder or prostate in men.
In patients with white blood cells in the urine, a urine culture is performed and a urinary cytology is used to locate abnormal cells. A blood test measuring serum creatinine is useful. Patients with significant protein in their urine, abnormally shaped red blood cells, or elevated creatinine levels need further evaluation for renal disease.
A complete urologic evaluation for hematuria includes x-rays of the kidneys and ureters. Traditional testing involves an intravenous pyelogram, where dye is injected into the blood and x-rays are made as the kidneys excrete the dye. Some physicians use imaging studies, such as a computerized tomography (CT) scan or CT urography.
When there is elevated creatinine or an allergy to x-ray dye, magnetic resonance imaging or retrograde pyelography can help evaluate the upper urinary tract. In retrograde pyelography, dye is injected into the ureters from the bladder, and x-rays are taken. After the initial tests, the patient empties the bladder and has a final x-ray.
However, none of these studies affords bladder evaluation. A cystoscopic evaluation is usually performed under local anesthesia using a flexible cystoscope, enabling examination of the inner lining of the bladder and urethra.
Significant proteinuria, red cell casts, renal insufficiency, or dysmorphic red blood cells in the urine in asymptomatic microscopic hematuria should prompt evaluation for renal parenchymal disease.
When no specific cause is identified, bladder and kidney stones, cancer, and other lifethreatening diseases can be ruled out. Other causes that remain may correct themselves, or the hematuria may remain idiopathic.
In 10% of cases, no cause for hematuria is found. However, studies show that urologic malignancy is later discovered in 1% to 3% of patients with negative test results. Follow-up is then recommended.
When bladder cancer is detected using a uroscope, the cancerous cells are often scraped from the lining of the bladder without invasive surgery. With kidney cancer, surgical removal of the malignancy is possible in some cases; in others, removal of the entire kidney is required.
The American Urological Association suggests repeating urinalysis and urine cystoscopy at six, 12, 24, and 36 months. Immediate reevaluation with cystoscopy and repeat imaging should be performed in the case of gross hematuria, abnormal urinary cytology, or irritating urinary symptoms, such as pain with urination or increased frequency of urination. If none of these symptoms recurs within three years, no further urologic testing is needed.