Hematuria

This page is for adult patients; for pediatric patients see hematuria (peds)

Background

  • Hematuria can be macroscopic/gross or microscopic
    • Microscopic hematuria generally defined as >3 RBCs per high-power field of an uncontaminated sample
  • Hematuria can also be divided into glomerular and nonglomerular causes
  • Make sure hematuria is not myoglobin (due to rhabdo), hemoglobinuria (due to hemolysis), or bleeding from non-urinary source (ex. menstruation)
  • Hematuria + pain suggests UTI or nephrolithiasis
  • Hematuria + no pain suggests malignancy, hyperplasia, or vascular cause

Common Causes

Clinical Features

Gross hematuria on urine sample.
Hematuria in a foley bag.

Types of hematuria

  • Initial hematuria
    • Blood at beginning of micturition with subsequent clearing
    • Suggests urethral disease
  • Intervoid hematuria
    • Blood between voiding only (voided urine is clear)
    • Suggests lesions at distal urethra or meatus
  • Total hematuria
    • Blood visible throughout micturition
    • Suggests disease of kidneys, ureters, or bladder
  • Terminal hematuria
    • Blood seen at end of micturition after initial voiding of clear urine
    • Suggests disease at bladder neck or prostatic urethra
  • Gross hematuria
    • Indicates lower tract cause
  • Microscopic hematuria
    • Tends to occur with kidney disease
  • Brown urine with RBC casts and proteinuria
    • Suggests glomerular source
  • Clotted blood
    • Indicates source below kidneys

Blunt Trauma[1]

Renal injuries are associated with:

  • Sudden deceleration injury without hematuria
  • Gross Hematuria
  • Microscopic Hematuria with Shock (SBP<90 mm Hg)
  • The degree of hematuria does not correlate with significance of renal injury

Differential Diagnosis

Hematuria

Sources of hematuria.

Evaluation

Macroscopic Hematuria algorithm

Workup

Labs

  • Urinalysis
    • Urine microscopy can show abnormal RBC morphologies suggesting glomerular source of hematuria
    • Microscopic hematuria associated with proteinuria suggests glomerular disease and requires further investigation (as an outpatient)
  • Urine dipstick may be performed quickly in some centers but has high false-positive rate[2]
  • CBC - for anemia and thrombocytopenia
  • BMP - for renal function
  • Coags


Imaging

  • Utilize multiphasic CT urography ("hematuria protocol") to assess for pathology in the kidney and urinary collecting system[3]
    • A noncontrast phase is useful for visualizing stones or hydronephrosis
    • A nephrographic phase has contrast enhancing renal parenchyma, useful for pyelonephritis and renal tumors
    • A delayed excretory phase visualizes urothelial and bladder tumors
  • Ultrasound useful to assess for hydronephrosis or a Abdominal Aortic Aneurysm
  • Ultimately, cystoscopy and/or kidney biopsies may be necessary as follow-up procedures after the final disposition

Diagnosis

  • Based on UA
    • Isolated hematuria with dysmorphic red cells or red cells with a decreased mean corpuscular volume (MCV), should prompt an evaluation for glomerulopathy (e.g., IgA nephropathy & Alport's syndrome)[4]
    • Isolated hematuria may be elusive. In some series, more than half of the patients have microhematuria with no definable cause.[5]

Management

  • Treat underlying cause
  • Gross hematuria
    • Often associated with intravesicular clot formation and bladder outlet obstruction
      • Use triple-lumen urinary drainage catheter with intermittent or continuous bladder irrigation
        • Adequate urinary drainage must be ensured; otherwise consult urology

Disposition

Outpaient

  • Outpatient management appropriate if:
    • Hemodynamically stable without life-threatening cause of hematuria
    • Able to tolerate oral fluids, antibiotics, and analgesics as indicated
    • Able to void
    • No significant anemia or acute renal insufficiency

Referral Considerations

  • Patients <40 yr: refer to primary care provider for repeat UA within 2wk
  • Patients >40 yr with risk factor for urologic cancer: refer to urologist within 2wk
    • Risk factors:
      • Smoking history
      • Occupational exposure to chemicals or dyes
      • History of gross hematuria
      • Previous urologic history
      • History of recurrent UTI
      • Analgesic abuse
      • History of pelvic irradiation
      • Cyclophosphamide use
      • Pregnancy
      • Known malignancy
      • Sickle cell disease
      • Proteinuria
      • Renal insufficiency
  • Consider nephrology referral for signs of glomerular hematuria such as concommittant AKI, proteinuria, dysmorphic RBCs, RBC casts

Admission

If:

See Also

References

  1. Mee S. et al. Radiographic assessment of renal trauma: A 10-year prospective study of patient selection. J Urology. 1989 May;141(5):1095-8
  2. Saleem MO, Hamawy K. Hematuria. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534213/
  3. Sharp VJ, Barnes KT, Erickson BA. Assessment of asymptomatic microscopic hematuria in adults. Am Fam Physician. 2013 Dec 1;88(11):747-54. PMID: 24364522.
  4. Ingelfinger, J. (2021). Hematuria in Adults. The New England Journal of Medicine, 385(2), 153–161.
  5. Ingelfinger, J. (2021). Hematuria in Adults. The New England Journal of Medicine, 385(2), 153–161

Video

{{#widget:YouTube|id=q4_O8kTArX4}}