What is the cause of hematuria in a patient with a 2+ occult blood test result?

From the Guidelines

Hematuria in a patient with a 2+ occult blood test result is a significant finding that requires further evaluation to determine the underlying cause, with potential causes including urinary tract infections, kidney stones, bladder or kidney tumors, glomerulonephritis, trauma, medications, or vigorous exercise. The 2+ reading indicates a moderate amount of blood in the urine, which necessitates a comprehensive diagnostic workup. Initial assessment should include a complete urinalysis with microscopic examination to confirm true hematuria (presence of red blood cells) versus other substances that can cause false positive occult blood results, such as myoglobin or hemoglobin 1. Additional diagnostic workup typically includes:

• Urine culture to rule out urinary tract infections
• Imaging studies like ultrasound or CT scan to evaluate the kidneys and bladder
• Possibly cystoscopy depending on risk factors and persistence of symptoms, as recommended by the American Urological Association 1 Certain medications like anticoagulants, NSAIDs, and some antibiotics can cause hematuria, as can menstruation in women. It's essential to note that even microscopic hematuria can indicate serious underlying conditions, so proper evaluation is necessary regardless of whether the blood is visible to the naked eye or only detected through testing 1. A proper hematuria workup should be performed in patients with un-evaluated hematuria, and considered in patients with tobacco exposure given the high risk of bladder cancer in smokers 1. The clinical diagnosis of interstitial cystitis/bladder pain syndrome (IC/BPS) requires a careful history, physical examination, and laboratory examination to document basic symptoms that characterize the disorder and exclude infections or other confusable disorders, including a proper hematuria workup 1. A thorough evaluation, including a complete medical history, physical examination, and diagnostic testing, is crucial to determine the underlying cause of hematuria and provide appropriate treatment.

From the Research

Urinalysis Results

The patient's urinalysis results show a 2+ occult blood test result, which indicates the presence of blood in the urine. The specific gravity of the urine is 1.026, which is within the normal range of 1.005-1.030. The pH of the urine is 5.5, which is within the normal range of 5.0-7.5. The urine color is yellow, and the appearance is clear. The WBC esterase test is negative, and the protein and glucose tests are also negative.

Possible Causes of Hematuria

The cause of hematuria in this patient is not immediately clear. However, according to 2, asymptomatic microscopic hematuria can be caused by a variety of factors, including urologic disease, anticoagulation therapy, and other medical conditions. The study suggests that a thorough medical history and physical examination, as well as laboratory and imaging studies, may be necessary to determine the cause of the hematuria.

Differential Diagnosis

Other possible causes of hematuria include:

• Urinary tract infections, which can be diagnosed by positive leukocyte esterase and nitrite tests, as mentioned in 3
• Kidney stones or other urologic conditions, which can cause blood to appear in the urine
• Medications, such as trimethoprim-sulfamethoxazole, which can cause hemolytic anemia, as reported in 4
• Appendicitis, which can cause abnormal urinalysis results, including positive occult blood, as noted in 5

False-Positive Test Results

It is also possible that the 2+ occult blood test result is a false positive, as mentioned in 6. This can occur when stool samples are collected from a toilet bowl contaminated with urine that contains blood.

Microscopic Examination

The microscopic examination of the urine may provide additional information about the cause of the hematuria. The presence of red or white blood cells, casts, or other abnormalities can help to diagnose the underlying condition. According to 3, a complete urinalysis includes physical, chemical, and microscopic examinations, and can provide valuable information about the patient's condition.

Next Steps

Further evaluation, including a thorough medical history, physical examination, and laboratory and imaging studies, may be necessary to determine the cause of the hematuria, as suggested by 2. The patient's medication list should also be reviewed to determine if any medications, such as trimethoprim-sulfamethoxazole, may be contributing to the hematuria, as reported in 4.