Key Points

• Hemophilia is a rare bleeding disorder that causes excessive bleeding and easy bruising. Hemophilia almost always occurs in males.
• If you have hemophilia, you have little to none of certain clotting factors, which are proteins that help blood clot. Thus, it can take a long time for your blood to clot after an injury or accident. Bleeding also often occurs internally, especially in the joints.
• There are two main types of hemophilia: A and B. People with hemophilia A have low levels of clotting factor VIII (8) or are missing it altogether. People with hemophilia B have low levels of clotting factor IX (9) or are missing it altogether.
• Hemophilia is usually caused by a defect in one of the genes that determine how the body makes certain blood-clotting factors. The genes are located on the X chromosomes, which determine whether a baby is a boy or girl.
• To diagnose hemophilia, your doctor will take a personal and family medical history, do a physical exam, and order blood tests. The tests will show whether you have a bleeding problem, whether it’s due to hemophilia or another cause, and how severe the disorder is.
• The main treatment for hemophilia is injecting the low or missing clotting factors directly into the bloodstream. This is called replacement therapy.
• Replacement therapy sometimes can be given on a long-term basis to prevent bleeding. People with severe hemophilia are more likely to receive this type of preventive replacement therapy.
• Replacement therapy also can be given as needed to stop bleeding when it occurs. This therapy is more common for people with milder hemophilia.
• Early treatment for bleeding is important to prevent or limit damage to joints, muscles, or other parts of the body.
• Replacement therapy is often done at home. Home treatment has many benefits, but being trained to do home treatments properly and safely is important.
• Physical activity is important for children and adults. Talk with your doctor about the type of activity that’s best for you or for your child and what to do to prevent injuries.
• Hemophilia treatment centers are located in many areas of the United States. These centers can provide treatment, education, and support to hemophilia patients, their families, and their health care providers.