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Paroxysmal nocturnal hemoglobinuria

Last reviewed: 30 Oct 2023
Last updated: 20 Sep 2018



History and exam

Key diagnostic factors

  • hemoglobinuria
  • Budd-Chiari syndrome
  • thrombosis
More key diagnostic factors

Other diagnostic factors

  • history of aplastic anemia
  • fatigue
  • anemia
  • abdominal pain
  • dysphagia and odynophagia
  • erectile dysfunction
  • dyspnea
  • infections
  • bleeding diathesis
  • neurologic signs and symptoms
Other diagnostic factors

Risk factors

  • aplastic anemia/hypoplastic bone marrow
  • myelodysplasia
More risk factors

Diagnostic investigations

1st investigations to order

  • urine dipstick
  • urine microscopy
  • CBC
  • reticulocyte count
  • serum LDH
  • unconjugated bilirubin
  • D-dimer
More 1st investigations to order

Investigations to consider

  • haptoglobin
  • flow cytometry for glycosylphosphatidylinositol anchor or anchored proteins
  • fluorescent aerolysin
  • immunotyping
  • antiglobulin (Coombs) test
  • serum iron, serum ferritin
  • serum creatinine and BUN
More investigations to consider

Treatment algorithm


classic PNH (hemolytic anemia): nonpregnant

classic PNH (hemolytic anemia): pregnant

PNH in the setting of another specific bone marrow disorder: nonpregnant

PNH in the setting of another specific bone marrow disorder: pregnant with thrombosis

PNH in the setting of another specific bone marrow disorder: pregnant without thrombosis

subclinical PNH: nonpregnant

subclinical PNH: pregnant


following acute clinical PNH with thrombosis: nonpregnant



Ilene Ceil Weitz, MD

Associate Professor of Clinical Medicine

Jane Anne Nohl Division of Hematology

Keck-USC School of Medicine

Los Angeles



ICW receives speaker honoraria from and undertakes consultancy for Alexion Pharmaceuticals.


Dr Ilene Ceil Weitz would like to gratefully acknowledge Dr Wendell F. Rosse, the previous contributor to this topic. WFR serves on advisory boards and educational faculties for Alexion Pharmaceuticals.

Peer reviewers

David Dingli, MD, PhD

Associate Professor of Medicine

Mayo Clinic




DD declares that he has no competing interests.

Panayiotis D. Ziakas, MD, MSc, PhD

Department of Pathophysiology

Medical School

University of Athens




PDZ declares that he has no competing interests.

  • Differentials

    • Autoimmune hemolytic anemia, warm antibody type
    • Microangiopathic hemolytic anemia
    • Paroxysmal cold hemoglobinuria
    More Differentials
  • Guidelines

    • Consensus guidelines to detect GPI‐deficient cells in paroxysmal nocturnal hemoglobinuria (PNH) and related disorders: Part 1 – clinical utility
    • The physician's guide to paroxysmal nocturnal hemoglobinuria (PNH)
    More Guidelines
  • Patient leaflets

    Deep vein thrombosis

    High blood pressure

    More Patient leaflets
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