What are the causes of non‑glomerular hematuria?

Non-Glomerular Causes of Hematuria

Non-glomerular hematuria originates from the urinary tract below the glomerulus—including the renal pelvis, ureters, bladder, prostate, and urethra—and is characterized by normal-shaped red blood cells (>80% isomorphic RBCs) with minimal or no proteinuria. 1

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Urologic Malignancies

• Bladder cancer (transitional cell carcinoma) is the most common malignancy causing hematuria, accounting for 30–40% of gross hematuria cases and 2.6–4% of microscopic hematuria cases. 2
• Renal cell carcinoma presents with hematuria in approximately 40–60% of cases and is best detected by multiphasic CT urography. 2
• Upper tract urothelial carcinoma (renal pelvis and ureter) is less common but carries significant morbidity; it is often associated with smoking and occupational chemical exposures. 2
• Prostate cancer may cause hematuria when locally advanced or when associated with benign prostatic hyperplasia. 2

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Benign Urologic Conditions

• Benign prostatic hyperplasia (BPH) is a common cause of hematuria in men over 50 years, resulting from friable prostatic vessels. 2
• Urolithiasis (kidney and ureteral stones) causes painful hematuria due to mucosal trauma; CT urography detects stones as small as 1–2 mm with high sensitivity. 2
• Urinary tract infection (UTI) produces hematuria with pyuria, dysuria, and positive urine culture; however, infection does not exclude concurrent malignancy and requires post-treatment re-evaluation if hematuria persists. 2
• Renal cysts and polycystic kidney disease may bleed spontaneously or after minor trauma. 2

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Trauma

• Blunt or penetrating renal trauma causes hematuria proportional to the degree of injury; contrast-enhanced CT is mandatory for high-energy mechanisms, multiorgan injury, or known congenital renal anomalies. 1, 2
• Bladder rupture presents with suprapubic pain, low urine output, and hematuria; CT cystography with retrograde filling is required for diagnosis. 3
• Urethral injury is suggested by blood at the urethral meatus with pelvic fractures or straddle injury; retrograde urethrography must precede catheter placement. 2

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Vascular and Anatomic Causes

• Renal artery or vein thrombosis may cause hematuria with flank pain and acute kidney injury. 2
• Arteriovenous malformations (AVMs) and renal infarction are rare causes of non-glomerular bleeding. 2
• Nutcracker syndrome (left renal vein compression) causes hematuria with variable proteinuria and is diagnosed by Doppler ultrasound. 2

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Metabolic Causes

• Hypercalciuria is a frequent metabolic contributor to microscopic hematuria in young males and predisposes to nephrolithiasis; a spot urine calcium-to-creatinine ratio is the preferred initial test. 2
• Hyperuricosuria similarly causes hematuria and stone formation. 2

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Infectious and Inflammatory Causes

• Acute cystitis (bacterial, viral, or fungal) produces hematuria with dysuria and frequency. 2
• Prostatitis in men may cause hematuria with pelvic pain and obstructive voiding symptoms. 2
• Schistosomiasis (endemic regions) causes chronic bladder inflammation and hematuria. 2
• Tuberculosis of the urinary tract presents with sterile pyuria and hematuria; urine culture for acid-fast bacilli is required. 2

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Hematologic and Systemic Causes

• Coagulopathies (hemophilia, von Willebrand disease) cause hematuria due to bleeding disorders but do not explain hematuria without underlying structural pathology. 2
• Anticoagulant and antiplatelet therapy (warfarin, DOACs, aspirin, clopidogrel) do not cause hematuria themselves but may unmask pre-existing urologic pathology; evaluation must proceed regardless of medication use. 2
• Sickle cell disease and sickle cell trait cause hematuria due to renal papillary necrosis and medullary ischemia. 2

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Exercise-Induced and Transient Causes

• Vigorous exercise causes transient hematuria that resolves within 48 hours of cessation; no further evaluation is needed if hematuria resolves. 2
• Sexual activity may cause transient hematuria in both men and women. 2
• Menstrual contamination in women produces false-positive dipstick results; obtain a catheterized specimen if clean-catch is unreliable. 2

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Drug-Induced Causes

• Cyclophosphamide causes hemorrhagic cystitis. 2
• Analgesic nephropathy (chronic NSAID use) may cause papillary necrosis and hematuria. 1
• Phenazopyridine (Azo dyes) interferes with urinalysis and should be discontinued 48–72 hours before testing. 2

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Key Diagnostic Distinctions

• Non-glomerular hematuria is characterized by >80% normal-shaped (isomorphic) RBCs on microscopy, absence of red cell casts, and minimal proteinuria (<0.5 g/g protein-to-creatinine ratio). 1, 2
• Tea-colored or cola-colored urine suggests glomerular bleeding, whereas bright red urine indicates lower urinary tract bleeding. 2
• Dysmorphic RBCs (>80%) and red cell casts are pathognomonic for glomerular disease and warrant nephrology referral in addition to urologic evaluation. 1, 2

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Common Pitfalls

• Never ignore gross hematuria, even if self-limited, due to a 30–40% malignancy risk that mandates urgent urologic referral. 2
• Do not attribute hematuria to anticoagulation or antiplatelet therapy without completing the full diagnostic work-up; these agents may unmask underlying pathology but do not cause hematuria. 2
• Infection does not exclude malignancy; persistent hematuria after UTI treatment requires full urologic evaluation with cystoscopy and CT urography. 2
• Dipstick testing alone has only 65–99% specificity; confirm true hematuria with microscopic urinalysis showing ≥3 RBCs/HPF before initiating any further work-up. 2