Hemophilia is a rare disorder in which the blood doesn't clot in the typical way because it doesn't have enough blood-clotting proteins (clotting factors). If you have hemophilia, you might bleed for a longer time after an injury than you would if your blood clotted properly.
Hemophilia is almost always a genetic disorder. Treatment includes regular replacement of the specific clotting factor that is reduced. Newer therapies that don't contain clotting factors also are being used.
Certain genes create clotting factors. In inherited hemophilia, the genes carrying instructions for making normal clotting factors mutate or change. The mutated genes may give instructions that end up making abnormal clotting factors or not enough clotting factors. That said, about 20% of all hemophilia cases are spontaneous, meaning someone has the disease even though there’s no family history of abnormal bleeding.
The most significant symptom is unusual or excessive bleeding or bruising.
People with hemophilia may develop large bruises after minor injuries. This is a sign of bleeding under their skin.
They may bleed for an unusually long time, whether that’s bleeding after surgery, bleeding after dental treatment or simply bleeding from a cut finger.
They may start bleeding for no apparent reason, such as sudden bloody noses.
How much bruising or bleeding people have depends on whether they have severe, moderate or mild hemophilia:
A healthcare provider will start by doing a complete history and physical examination. If you have hemophilia symptoms, the provider will ask about your family’s medical history. Providers may do the following tests:
Complete blood count (CBC): Healthcare providers use this test to check on all of your blood cells, with a focus on your red blood cells. They count your red blood cells and evaluate your red blood cells’ size and shape. Healthcare providers may use this test to check on your vitamin B12 or B9 levels.
Prothrombin time (PT) test: Providers use this test to see how quickly your blood clots.
Activated partial thromboplastin time test: This is another blood test to time blood clot formation.
Specific clotting factor test(s): This blood test show levels of specific clotting factor levels (such as factor 8 and factor 9).
They treat hemophilia by boosting clotting factor levels or replacing missing clotting factors (replacement therapy).
In replacement therapy, you receive human plasma concentrates or lab-made (recombinant) clotting factors. In general, only people with severe hemophilia need regular replacement therapy. People with mild or moderate hemophilia who need surgery may receive replacement therapy. They may also receive antifibrinolytics, a medication that keeps blood clots from breaking down.
Blood factor concentrates are made from donated human blood that’s been treated and screened to reduce the risk of transmitting infectious diseases, such as hepatitis and HIV. People receive replacement factors via intravenous infusion (IV).
If you have severe hemophilia and frequent bleeding episodes, your healthcare provider may prescribe prophylactic factor infusions to prevent bleeding.