Rare Bleeding Disorders

Factor XI Deficiency

About 1 in every 100,000 people have a deficiency of factor XI, another clotting factor protein that helps the body form protective blood clots. Many people with factor XI deficiency have mild symptoms, but this can vary.1

Symptoms of factor XI deficiency may include1:

  • Abnormal bleeding during or after injury, surgery, childbirth, or dental procedures
  • Heavy or prolonged periods
  • Nosebleeds and/or easy bruising
  • Blood in the gastrointestinal or urinary tract


Factor XI concentrate is the preferred treatment, but antifibrinolytic drugs and fibrin glue may also be used. Heavy periods may be treated with birth control pills or antifibrinolytics.1


  1. What Are Rare Clotting Factor Deficiencies? Montreal, QC: World Federation of Hemophilia; 2009.