Description

Gross (visible) or microscopic (nonvisible) blood in urine, either symptomatic or asymptomatic

Epidemiology

Prevalence
Children: gross: 0.13%; asymptomatic microscopic hematuria (AMH): 0.4–4.1%; adults: AMH: 0.9–17%

Etiology and Pathophysiology

• Trauma
  • Exercise-induced (resolves within 24 hours of ceasing activity)
  • Abdominal trauma or pelvic fracture with renal, bladder, or ureteral injury
  • Iatrogenic from abdominal or pelvic surgery, indwelling catheters, or foreign body
  • Physical/sexual abuse
• Neoplasms
  • Urologic malignancies or benign tumors
  • Endometriosis of the urinary tract (suspect in females with cyclic hematuria)
• Inflammatory/infectious causes
  • UTI: most common cause of hematuria in adults
  • Renal diseases: radiation nephritis and cystitis, acute/chronic tubulointerstitial nephritis (due to drugs, infections, systemic disease)
  • Glomerular disease
    • Goodpasture syndrome (antiglomerular basement membrane disease; autoimmune; associated pulmonary hemorrhage)
    • IgA nephropathy
    • Lupus nephritis
    • Henoch-Schönlein purpura
    • Membranoproliferative, poststreptococcal, or rapidly progressive glomerulonephritis (GN)
    • Wegener granulomatosis
  • Endocarditis/visceral abscesses
  • Infections: schistosomiasis, TB, syphilis
• Metabolic causes
  • Stones (85% have hematuria.)
    • Hypercalciuria: a common cause of gross and microscopic hematuria in children
    • Hyperuricosuria
    • Drugs that cause calculi such as acyclovir
• Congenital/familial causes
  • Cystic disease: polycystic kidney disease, solitary renal cyst
  • Benign familial hematuria or thin basement membrane nephropathy (autosomal dominant)
  • Alport syndrome (X-linked in 80%; hematuria, proteinuria, hearing loss, corneal abnormalities)
  • Fabry disease (X-linked recessive inborn error of metabolism; vascular kidney disease)
  • Nail–patella syndrome (autosomal dominant; nail and patella hypoplasia; hematuria in 33%)
  • Renal tubular acidosis type 1 (autosomal dominant or autoimmune)
• Hematologic causes
  • Bleeding dyscrasias (e.g., hemophilia)
  • Sickle cell anemia/trait (renal papillary necrosis)
• Vascular causes
  • Hemangioma
  • Arteriovenous malformations (rare)
  • Nutcracker syndrome: compression of left renal vein, renal parenchymal congestion
  • Renal artery/vein thrombosis
  • Arterial emboli to kidney
• Chemical causes
  • Aminoglycosides, cyclosporine, analgesics, oral contraceptives, Chinese herbs, cyclophosphamide, anticoagulants warfarin ([Coumadin], apixaban [Eliquis], rivaroxaban [Xarelto]), sulfa drugs, penicillins
• Obstruction
  • Strictures or posterior urethral valves
  • Hydronephrosis from any cause
  • Benign prostatic hyperplasia: Rule out other causes of hematuria.
• Other causes: loin pain hematuria (most often in young women on oral contraceptives)

Risk Factors

• Smoking
• Occupational exposures (dyes, rubber, or tire manufacturing, petrochemicals)
• Medications (e.g., cyclophosphamide, pioglitazone therapy >1 year)
• Pelvic radiation
• Chronic infection, especially with calculi
• Recent upper respiratory tract infection
• Positive family history of stones, GN, or cancer
• Chronic indwelling foreign body