Hemophilia is an inherited bleeding disorder that affects the ability of blood to clot. Blood clots normally form after injury to the skin and allow the skin to heal normally. In patients with hemophilia, blood clots don't form properly, leading to bleeding that ranges from mild to severe.
Hemophilia is caused by defects in proteins called clotting factors. Patients with hemophilia have either defective forms of clotting factor VIII or clotting factor IX. These proteins function in coagulation, during which a protein net is formed around torn blood vessels to stop the bleeding.
Symptoms of hemophilia usually appear during infancy or early childhood. Due to an inability to properly form clots, patients with hemophilia experience prolonged bleeding in response to injuries, such as scrapes, bruises, cuts, or nosebleeds, as well as after surgical procedures. Some patients with hemophilia may experience pain and swelling in their joints, including in the knees, elbows, ankles, shoulders, and hips. This is due to internal bleeding in the joint. Women with hemophilia may experience severe bleeding during menstruation or child birth.
In the United States, about 17,000 people have hemophilia. About one in 7,500 live male births has hemophilia and about one in 25,000,000 live female births has hemophilia.
Currently, there is no known cure for hemophilia. However, if treated properly, patients can live normal, healthy lives. Patients with hemophilia may receive clotting factor replacement therapy to restore the missing clotting factor function.

Related Terms

Acquired hemophilia, bleeding, blood clot, Christmas disease, clotting factor, coagulation, factor IX deficiency, factor VIII deficiency, hematochezia, hematuria, hemophilia A, hemophilia B, hemophilia B Leyden, hemorrhage, inherited genetic condition, platelets.