Hemophilia refers to a group of bleeding disorders in which it takes a long time for the blood to clot.
Causes, incidence, and risk factors
Blood clotting factors are substances in the blood that help form a clot. When one or more of these clotting factors are missing, there is a higher chance of bleeding.
In most cases, the disorder is passed down through families (inherited). It most often affects males.
The main symptom of hemophilia is bleeding. Mild cases may go unnoticed until later in life, when they occur during surgery or after trauma.
In more severe cases, serious bleeding may occur without any cause. Internal bleeding may occur anywhere. Bleeding into joints is common.
Signs and tests
Most often, hemophilia is diagnosed after a person has an abnormal bleeding episode or when there is a known family history of the condition.
TreatmentStandard treatment involves replacing the missing clotting factor.
Most people with hemophilia are able to lead relatively normal lives. However, some patients have significant bleeding events, most commonly chronic bleeding into the joint spaces.
A small percentage of people with hemophilia may die from severe bleeding.
Kumar V, Abbas AK, Fausto N. Robbins and Cotran Pathologic Basis of Disease. 7th ed. St. Louis, Mo: WB Saunders; 2005:655-656.
Kessler C. Hemorrhagic disorders: Coagulation factor deficiencies. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 180.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.