What are the signs and symptoms of inhibitors?

A person with hemophilia who develops inhibitors does not get better after standard treatment with factor concentrates. Inhibitors are suspected when the person, family members, or medical staff notice that treatment is less effective than it used to be. Signs and symptoms of inhibitors include:

  • A bleed is not promptly controlled with the usual dose of factor concentrates.
  • Normal treatment seems less and less effective.
  • Bleeding is more and more difficult to control.

Today, inhibitors are often discovered during a routine laboratory test. A diagnosis based on signs and symptoms of inhibitors should be confirmed by repeated laboratory tests. 

Content developed by the WFH Inhibitors Working Group

Updated December 2014


Find a treatment centre


Search the Publications Library


Read Hemophilia World


Access Haemophilia Journal