What is PNH?
PNH is an acquired mutation that causes some or all of your body’s red blood cells (RBCs) to be destroyed by a process called hemolysis.1-3 PNH is a complex disease with signs and symptoms that are nonspecific, unpredictable, and often similar to those of other diseases. In addition, PNH presents uniquely in each person. If you have PNH, some or all of your RBCs may be missing an important protective protein. Without this protein, RBCs are prone to destruction by a part of your body’s defense system called complement.1-3
Even though you can’t feel it, hemolysis is constant, silent, and can be life threatening.4 Like other chronic diseases, such as diabetes or hypertension, PNH can result in serious health problems if not treated. Common symptoms associated with PNH include stomach pain, difficulty swallowing, anemia, shortness of breath, and tiredness (fatigue). More serious complications can include blood clots, kidney failure, and damage to vital organs. People with PNH may have different symptoms that can unpredictably get worse (such as during times of stress) or better from time to time. However, all people with PNH experience chronic hemolysis.
People with PNH may have other medical conditions that affect the function of their bone marrow such as aplastic anemia (AA) or myelodysplastic syndromes (MDS). Unlike PNH, which destroys RBCs, these diseases may reduce the production of blood cells and further complicate PNH.5 If you have PNH in combination with AA or MDS, talk to your doctor — it’s important to effectively treat all the conditions you may have.
If you have PNH and are considering pregnancy, there are risks involved to both mother and child that should be discussed with your physician — and your partner. If you do choose to become pregnant, you will likely be referred to a high-risk pregnancy specialist and monitored closely for the duration of the pregnancy. But don’t worry, PNH cannot be inherited from parents, nor can it be passed on to children.
How PNH got its name
When PNH was first named, not much was known about it. The name literally means episodic hemoglobin (a component of blood) in the urine, which occurs at night. But actually, less than one-third of people with PNH experience hemoglobin in their urine at diagnosis.6 In fact, PNH is a complex disease that affects many parts of the body and hemolysis (the destruction of red blood cells) does not only happen at night — it happens all the time.
PNH is a rare disease
PNH affects approximately 8,000 to 10,000 people in North America and Western Europe.7 It can affect men and women of all races and ages but most commonly affects people between the ages of 20 to 40 years old.
Although PNH is rare, the medical community understands a lot about the way the disease works — and there are doctors who are experienced in treating it.