From the Guidelines
The initial investigation and management for microscopic hematuria involves a comprehensive evaluation to identify the underlying cause, starting with a repeat urinalysis to confirm the presence of microscopic hematuria, followed by a detailed medical history, physical examination, laboratory tests, and imaging studies as necessary. The evaluation should include a thorough history focusing on risk factors for urologic malignancy (smoking, chemical exposures, age >35 years), recent infections, medication use (anticoagulants, NSAIDs), and family history of kidney disease 1. Physical examination should include blood pressure measurement and abdominal examination. Laboratory tests should include serum creatinine, blood urea nitrogen, complete blood count, and urine culture to rule out infection. Imaging studies are essential, typically starting with renal ultrasound, followed by CT urography if no cause is identified 1.
- Key considerations in the evaluation of microscopic hematuria include:
- Confirming the presence of microscopic hematuria with a repeat urinalysis
- Obtaining a detailed medical history focusing on risk factors for urologic malignancy
- Performing physical examination, including blood pressure measurement and abdominal examination
- Conducting laboratory tests, including serum creatinine, blood urea nitrogen, complete blood count, and urine culture
- Utilizing imaging studies, such as renal ultrasound and CT urography, as necessary
- Cystoscopy is recommended for adults over 35 years with risk factors for bladder cancer, and if glomerular disease is suspected, a nephrology referral is appropriate 1.
- Management depends on the identified cause, including treating infections with appropriate antibiotics, stopping offending medications, or referring to urology or nephrology for specific conditions.
- Follow-up urinalysis should be performed after treatment to ensure resolution, and it's essential to remember that microscopic hematuria can indicate serious conditions like malignancy or glomerulonephritis, but can also be benign, especially in younger patients without risk factors 1.
From the Research
Initial Investigation for Microscopic Hematuria
The initial investigation for microscopic hematuria includes:
- A thorough history and physical examination to determine potential causes and assess risk factors for malignancy 2, 3
- Laboratory tests to rule out intrinsic renal disease 2
- Imaging of the urinary tract, such as ultrasonography of the kidneys and bladder 3
- Urine microscopy to confirm the presence of three or more erythrocytes per high-power field 3, 4
Management of Microscopic Hematuria
The management of microscopic hematuria involves:
- Referral to nephrology and urology subspecialists if no benign cause is found 2
- A risk-adapted diagnostic strategy for the evaluation of asymptomatic microhematuria (aMH) 3
- Augmented diagnostic evaluation with urethrocystoscopy, urine cytology, and CT urography for patients with non-glomerular aMH who have risk factors such as smoking, advanced age, and male sex 3
- Follow-up checks at six-month intervals for patients with isolated glomerular hematuria 3
Diagnostic Evaluation
The diagnostic evaluation for microscopic hematuria may include:
- Intravenous urography (IVU) as a secondary radiographic study when microhematuria has persisted for 3 months after the initial workup with renal ultrasound (US) and cystoscopy was negative 5
- Urine cytology, although its use is not recommended as a routine screening test for hematuria due to its low sensitivity and positive predictive value 6