Diagnoses & Conditions

Fibrinogen (Factor I) Deficiency

Understanding Fibrinogen Deficiency

Fibrinogen is another name for factor I. Fibrinogen deficiency is an inherited bleeding disorder caused by a problem with factor I. There are several disorders related to congenital fibrinogen defects. Patients with afibrinogenemia or hypofibrinogenemia do not produce any or enough fibrinogen. Patients with dysfibrinogenemia produce fibrinogen but it does not work the way it should. Patients with hypodysfibrinogenemia produce a decreased amount of fibrinogen which does not work properly. When the body produces less fibrinogen than it should, or if the fibrinogen is not working properly, the clotting reaction is blocked prematurely, and a blood clot does not form. Factor I deficiency affects both males and females. It may be inherited from both or from only one parent.

Symptoms of Fibrinogen Deficiency

The symptoms of factor I deficiency differ depending on which form of the disorder a person has. For afibrinogenemia, symptoms include nosebleeds, easy bruising, heavy or prolonged menstrual bleeding, muscle bleeds, joint bleeds, bleeding from the umbilical cord stump after birth, bleeding in the mouth, particularly after dental surgery or tooth extraction, abnormal bleeding during or after injury, surgery, or childbirth, abnormal bleeding after circumcision, problems during pregnancy (including miscarriage). Other reported symptoms include bleeding in the gut (gastrointestinal hemorrhage), bleeding in the central nervous system (the brain and spinal cord) and formation of blood clots (thrombosis). For hypofibrinogenemia, symptoms are similar to those seen in afibrinogenemia. For dysfibrinogenemia, symptoms depend on how the fibrinogen (which is present in normal quantities) is functioning. Some people have no symptoms at all. Other people experience bleeding (similar to those seen in afibrinogenemia) and others show signs of thrombosis (abnormal blood clots in blood vessels) instead of bleeding. For hypodysfibrinogenemia, symptoms are variable and depend on the amount of fibrinogen that is produced and how it is functioning.1

Diagnosing Fibrinogen Deficiency

Diagnosing fibrinogen deficiency is done through a variety of blood tests, including those that measure the amount of fibrinogen in the blood.

Treating Fibrinogen Deficiency

Treatment available for fibrinogen deficiency includes fibrinogen concentrate, cryoprecipitate and fresh frozen plasma.


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