Hemophilia A Complications

Complications of hemophilia A can occur as a result of either the condition or its treatment, such as replacement therapy. Complications can include1,2:

  • Joint damage
  • Hepatitis2
  • Development of inhibitors, which are antibodies to clotting factors

Joint damage1

The most common complication of hemophilia is joint damage, or hemophilic arthropathy, that can occur when there is bleeding into joints. This is the most common clinical complication of hemophilia. Bleeding into knees, elbows, ankles, shoulders, and hips can lead to chronic swelling, pain, immobility, and eventual joint deformity.1


Patients with bleeding disorders should receive vaccines for hepatitis A and B. According to the National Hemophilia Foundation, there have been no reports of hepatitis C transmission through the use of factor therapies since 1997, thanks to improved donor screening and manufacturing methods.3

Symptoms of hepatitis can include fatigue, nausea, vomiting, joint aches, vague abdominal discomfort, jaundice, and weight loss.3


In some patients with hemophilia, the immune system produces an antibody that inhibits, or partly stops, the action of replacement blood products and prevents blood clots from being formed. This antibody is known as an inhibitor. Inhibitors develop as a result of an abnormal immune response to replacement therapy.1

An inhibitor makes treatment of bleeding episodes more difficult because it destroys the clotting factor before it has a chance to stop the bleeding.1


  • Affect up to one-third of people with severe or moderately severe hemophilia A
  • Develop most often during childhood, especially during the first 50 exposure days (the period of time after starting a recombinant factor VIII replacement therapy)
  • Are more common in African Americans and Hispanics than in other populations

The risk of developing an inhibitor is higher if someone in the patient’s family also has an inhibitor.4

How do I know if I have an inhibitor?

When bleeding does not stop after being treated with replacement therapy, an inhibitor may be suspected. However, many people who develop inhibitors do not show any symptoms commonly associated with the presence of inhibitors. In these cases, inhibitors are most often discovered by laboratory testing during regular physician visits.4

If an inhibitor is suspected, confirmation can be made using a blood test called the Bethesda inhibitor assay. This test measures the presence and amount of antibodies directed against a coagulation factor in a person’s blood after they have received factor replacement therapy.6


  1. Inhibitors and other complications. National Hemophilia Foundation website. https://www.hemophilia.org/Bleeding-Disorders/Inhibitors-Other-Complications. Accessed October 14, 2014.
  2. MASAC recommendations for hepatitis A and B immunization of individuals with bleeding disorders. National Hemophilia Foundation website. http://www.hemophilia.org/Researchers-Healthcare-Providers/Medical-and-Scientific-Advisory-Council-MASAC/All-MASAC-Recommendations/Recommendations-for-Hepatitis-A-and-B-Immunization-of-Individuals-with-Bleeding-Disorders. Published November 18, 2001. Accessed October 14, 2014.
  3. Riley L, Womack M. Hepatitis and hemophilia. In: Nurses’ Guide to Bleeding Disorders. New York, NY: National Hemophilia Foundation; 2012. https://www.hemophilia.org/sites/default/files/document/files/Nurses-Guide-Chapter-10-Hepatitis-and-Hemophilia.pdf. Accessed October 23, 2014.
  4. DiMichele DM. Inhibitors in Hemophilia: A Primer. 4th ed. Montreal, QC. World Federation of Hemophilia; 2008. http://www1.wfh.org/publication/files/pdf-1122.pdf. Accessed October 22, 2014.
  5. Why some patients develop inhibitors. National Hemophilia Foundation website. https://www.hemophilia.org/Bleeding-Disorders/Inhibitors-Other-Complications/Inhibitors-for-Providers/Why-Some-Patients-Develop-Inhibitors-. Accessed October 22, 2014.
  6. How do you know if you have an inhibitor? National Hemophilia Foundation website. https://www.hemophilia.org/Bleeding-Disorders/Inhibitors-Other-Complications/Inhibitors-for-Consumers/How-do-you-know-if-you-have-an-inhibitor. Accessed December 17, 2014.