Population Trends

Hemophilia occurs in about 1 of every 5,000 people. Hemophilia A is most common and people with hemophilia A have up to 6% to 49% normal clotting in their blood. Hemophilia B is the second most common and people with it have up to 5% to 50% normal clotting in their blood. About 20,000 males in the United States are living hemophilia. Hemophilia also affects all racial groups and ethnic groups.