From the Guidelines
Asymptomatic hematuria should be evaluated with a confirmatory microscopic urinalysis demonstrating 3 or more erythrocytes per high-powered field before initiating further assessment, as recommended by the American College of Physicians 1. The management of asymptomatic hematuria involves a stepwise approach to identify the underlying cause, balancing the need for diagnosis with the risk of unnecessary interventions.
Initial Evaluation
- A complete urinalysis is essential to confirm the presence of hematuria, with a threshold of more than 3 red blood cells per high-power field on microscopic examination 1.
- A thorough history and physical examination should be conducted to identify risk factors for urologic malignancy, recent infections, medication use, and family history of kidney disease.
Risk Stratification
- Patients with gross hematuria, even if self-limited, should be referred for further urologic evaluation 1.
- Adults with microscopically confirmed hematuria without a demonstrable benign cause should be considered for urology referral for cystoscopy and imaging 1.
Diagnostic Approach
- The initial evaluation of hematuria should not include urinary cytology or other urine-based molecular markers for bladder cancer detection 1.
- For patients over 35 years old or those with risk factors for urologic malignancy, referral to a urologist for cystoscopy and upper tract imaging is recommended.
- Younger patients without risk factors may be monitored with repeat urinalysis in 6-12 months, with urologic evaluation considered if hematuria persists.
Treatment
- No specific medications are indicated for asymptomatic hematuria itself, as treatment targets the underlying cause. The rationale for this approach is based on the guidance from the American College of Physicians, emphasizing the importance of confirming hematuria and stratifying patients by risk to guide further evaluation and potential referral to specialists 1.
From the Research
Management of Asymptomatic Hematuria
- Asymptomatic microscopic hematuria is occasionally detected on routine urinalysis, and its cause should be investigated with a thorough medical history and a focused physical examination 2
- Laboratory and imaging studies, such as intravenous pyelography, renal ultrasonography or retrograde pyelography, may be required to determine the degree and location of the associated disease process 2
- Cystourethroscopy is performed to complete the evaluation of the lower urinary tract 2
- The evaluation of asymptomatic hematuria should include a thorough history and physical to determine potential causes and assess risk factors for malignancy 3
- Risk of malignancy with gross hematuria is greater than 10%, and prompt urologic referral is recommended 3
Diagnostic Approach
- Urine cytology, urine culture, imaging studies, and cystoscopy are often involved in the clinical evaluation of patients with asymptomatic hematuria 4
- The most common differential diagnosis for both microscopic and gross hematuria in adults includes infection, malignancy, and urolithiasis 4
- Patients who have no identifiable cause after an extensive workup should be monitored for early detection of malignancy or occult renal disease 4
Special Considerations
- Microscopic hematuria associated with anticoagulation therapy is frequently precipitated by significant urologic pathology and therefore requires prompt evaluation 2
- Certain medications, such as trimethoprim/sulfamethoxazole, can cause acute kidney injury and should be considered in the evaluation of asymptomatic hematuria 5