Paroxysmal nocturnal hemoglobinuria (PNH) is an ultra-rare, life-threatening blood disorder in which chronic, uncontrolled activation of the complement system leads to chronic haemolysis – the destruction of red blood cells.1,2

PNH develops without warning and can occur in men and women of all races, backgrounds and ages.3 While the average age of onset is in the early 30s, approximately 10 percent of patients first develop symptoms at age 21 or younger.4

PNH often goes unrecognized, with delays in diagnosis ranging from one to more than 10 years.2 The condition has been identified more commonly among patients with disorders of the bone marrow.5-7

PNH is a complex disease with signs and symptoms that are nonspecific and often similar to those of other diseases, making it difficult to detect and diagnose. In addition, because PNH is so rare, overall awareness of the disease and its natural history has been very limited. Although PNH symptoms can vary widely from patient to patient, some common symptoms include:4-9

  • Stomach pain
  • Difficulty swallowing
  • Severe anaemia
  • Shortness of breath
  • Dark-coloured urine (hemoglobinuria)
  • Disabling fatigue
  • Erectile dysfunction
  • Pain

If left untreated, the effects of PNH can be serious and life-threatening. Without treatment, approximately one-third of patients with PNH do not survive more than five years from the time of diagnosis2 due to serious complications including blood clots and kidney failure.2,10 Patients with PNH also suffer from severe quality-of-life issues that force them to modify their daily activity.9

Today, a growing number of physicians recognize the importance of accurate diagnosis and early intervention, and are following the international PNH Testing Guidelines developed in 2010 to test people with a greater likelihood of having PNH.

For more information about PNH, please visit


  1. Hill A, Richards SJ, Hillmen P. Recent developments in the understanding and management of paroxysmal nocturnal haemoglobinuria. Br J Haematol 2007 May;137(3):181-92.
  2. Hillmen P, Lewis SM, Bessler M, Luzzatto L, Dacie JV. Natural history of paroxysmal nocturnal hemoglobinuria. N Engl J Med 1995 Nov 9;333(19):1253-8.
  3. Socie G, Mary JY, de Gramont A., Rio B, Leporrier M, Rose C, et al. Paroxysmal nocturnal haemoglobinuria: long-term follow-up and prognostic factors. French Society of Haematology. Lancet 1996 Aug 31;348(9027):573-7.
  4. Parker C, Omine M, Richards S, Nishimura J, Bessler M, Ware R, et al. Diagnosis and management of paroxysmal nocturnal hemoglobinuria. Blood 2005 Dec 1;106(12):3699-709.
  5. Wang H, Chuhjo T, Yasue S, Omine M, Naka S. Clinical significance of a minor population of paroxysmal nocturnal hemoglobinuria-type cells in bone marrow failure syndrome. Blood. 2002;100 (12):3897-3902.
  6. Iwanga M, Furukawa K, Amenomori T, et al. Paroxysmal nocturnal haemoglobinuria clones in patients with myelodysplastic syndromes. Br J Haematol. 1998;102 (2):465-474.
  7. Maciejewski JP, Risitano AM, Sloand EM, et al. Relationship between bone marrow failure syndromes and the presence of glycophosphatidyl inositol-anchored protein-deficient clones. Br J Haematol. 2001;115:1015-1022.
  8. Rosse W. Paroxysmal Nocturnal Hemoglobinuria. Hoffman: Hematology: Basic Principles and Practice. 3 ed. Churchill Livingstone, Inc.; 2000.
  9. Meyers G, Weitz I, Lamy T, Cahn JY, Kroon HA, Severino B, et al. Disease-related symptoms reported across a broad population of patients with paroxysmal nocturnal hemoglobinuria. ASH Annual Meeting Abstracts 2007 Nov 16;110(11):3683.
  10. Nishimura J, Kanakura Y, Ware RE, Shichishima T, Nakakuma H, Ninomiya H, et al. Clinical course and flow cytometric analysis of paroxysmal nocturnal hemoglobinuria in the United States and Japan. Medicine (Baltimore) 2004 May;83(3):193-207.