What is PNH?

PNHA disease where red blood cells are created without a protective protein. This causes them to burst (a process called hemolysis) and can result in serious health problems. Signs and symptoms include stomach pain, difficulty swallowing, anemia, shortness of breath, and fatigue. Life-threatening complications from PNH include blood clots, kidney failure, and damage to organs. is a serious disease. It destroys an important part of your blood—the red blood cellsA type of cell found in your blood that delivers oxygen and removes waste (carbon dioxide) in your body. Red blood cells affected by PNH are attacked and destroyed because they are missing a protective protein.— and can be life-threatening. Living with PNH can be scary, and the facts about it can be scary too.1

  • 35% of patients with PNH die within 5 years of being diagnosed with it2
  • PNH can be devastating, causing organ damage, pain, and impairing your quality of life3-5
  • The fact that red blood cells are destroyed in PNH is bad because red blood cells have the important task of helping to deliver oxygen and remove waste from your body3

PNH is an acquiredNot inherited or present at birth, but developing after birth. disease, which means it develops in some people over time. In PNH, a change occurs in the stem cellsA type of cell in the body that is able to develop into many different types of cells in the body (for example, blood cells, skin cells, intestinal cells, etc). Stem cells serve as a repair system for the body. in the body, including in the bone marrowThe soft tissue inside your large bones. It works to create the cells in your blood: red blood cells, white blood cells, and platelets., where red blood cells are produced. The stem cell change causes the lifelong production of "bad" cells—cells that are missing an important protective proteinProteins are the building blocks of life. The body needs protein to repair and maintain itself. In PNH, some or all red blood cells lack an important protective protein. Without this protein, PNH red blood cells are destroyed by complement, part of the body’s natural defense system, resulting in hemolysis.. Without the protein, your body's natural defense system destroys PNH red blood cells. This destruction is known as hemolysisThe destruction of red blood cells by complement, a part of the body’s natural defense system. Hemolysis is the main cause of the signs, symptoms, and serious health problems in PNH, including some that are life-threatening..1,2

Hemolysis happens constantly and at high rates in PNH, which could put you at risk for serious health problems.1,6,7 Hemolysis is the main cause of the major health problems in PNH, including the most severe.1 Reducing hemolysis is key to managing your PNH.4 In addition, the signs and symptoms of PNH are often similar to other diseases.7,8 This is what makes PNH tough to diagnose.


The earlier PNH is diagnosed, however, the sooner your doctor can begin to treat you. Early treatment is important for improving your condition.9,10


  • PNH is a serious, unpredictable, and life-threatening disease5
  • PNH is progressiveA progressive disease is one that gets worse over time.. This means your disease can get worse over time, increasing your risk of major PNH health problems1
  • Everyone experiences PNH differently, making it difficult to diagnose7,8
  • PNH is treatable. There's a lot you can do

PNH is a rare disease, but you are not alone

PNH patient portrayal PNH patient portrayal
  • It affects about 8000 to 10,000 people in North America and Western Europe
  • Both men and women can get PNH
  • PNH occurs across all races
  • PNH can occur at any age; the average age at diagnosis is in the early 30s11

Understanding the disease is the first step toward changing the way you see PNH.

To get more insight into the disease and connect with the PNH community, watch patients share their stories, attend PNH events in your area, or talk to someone who can help you manage your PNH.

Click on a word that is underlined with a light dotted line and an explanation of that word will appear.

PNH Patient Batina video

Discover how Batina, a real PNH patient, first learned about her disease.

PNH Expert Doctor Farber video

Learn about common complications patients with PNH may experience from Dr. Charles M. Farber, a doctor and scientist of blood and blood diseases.

PNH Patient Scott video

See Scott, an actual PNH patient, describe how he learned he had PNH.

References: 1. Brodsky RA. Blood Rev. 2008;22:65-74. 2. Hillmen P, Lewis SM, Bessler M, et al. N Engl J Med. 1995;333:1253-1258. 3. Rother RP, Bell L, Hillmen P, et al. JAMA. 2005;293:1653-1662. 4. Rother RP, Rollins SA, Mojcik CF, et al. Nat Biotechnol. 2007;25:1256-1264. [Published correction appears in Nat Biotechnol. 2007;25:1488]. 5. Brodsky RA. Paroxysmal nocturnal hemoglobinuria. In: Hoffman R, Benz EJ Jr, Shattil SJ, et al, eds. Hematology: Basic Principles and Practice. 4th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2005:419-427. 6. Rachidi S, Musallam KM, Taher AT. Eur J Intern Med. 2010;21:260-267. 7. Rosse WF. Paroxysmal nocturnal hemoglobinuria. In: Hoffman R, Benz EJ Jr, Shattil SJ, et al, eds. Hematology: Basic Principles and Practice. 3rd ed. New York, NY: Churchill Livingstone; 2000:331-342. 8. Parker C, Omine M, Richards S, et al; for International PNH Interest Group. Blood. 2005;106:3699-3709. 9. Borowitz MJ, Craig FE, DiGiuseppe JA, et al; for Clinical Cytometry Society. Cytometry Part B. 2010;78B:211-230. 10. Richards SJ, Barnett D. Clin Lab Med. 2007;27:577-590. 11. Socié G, Mary J-Y, de Gramont A, et al; for the French Society of Haematology. Lancet. 1996;348:573-577.