Key Points

• Hemophilia is a rare bleeding disorder in which your blood doesn't clot as it should.
• If you have hemophilia, you may bleed for a longer time than others after an injury. You also may bleed internally, especially in your knees, ankles, and elbows. This bleeding can damage your organs or tissues and may be life threatening.
• If you have hemophilia, you're missing or have low levels 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.
• There are two main types of hemophilia. People who have hemophilia A have little to no clotting factor VIII (8). People who have hemophilia B have little to no clotting factor IX (9).
• Hemophilia usually is 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. Hemophilia usually only occurs in males (with very rare exceptions).
• The major signs and symptoms of hemophilia are excessive bleeding and easy bruising. The extent of bleeding depends on the type and severity of the hemophilia. Bleeding can occur on the body's surface (external bleeding) or inside the body (internal bleeding).
• Your doctor will diagnose hemophilia based on your personal and family medical histories, a physical exam, and the results from blood tests. The test results will show whether you have hemophilia, what type of hemophilia you have, and how severe it is.
• The main treatment for hemophilia is replacement therapy. This treatment involves injecting clotting factors directly into the bloodstream. You may have replacement therapy on a regular basis to prevent bleeding or as needed to stop bleeding when it occurs.
• Replacement therapy often is done at home. Home treatment has many benefits, but being trained to do home treatments properly and safely is important.
• Early treatment for bleeding is important to prevent or limit damage to joints, muscles, or other parts of the body.
• Other treatments for hemophilia include treatment with a man-made hormone and medicines. Researchers also are studying gene therapy as a potential treatment for hemophilia.
• 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.
• If you or your child has hemophilia, you can take steps to prevent bleeding problems. Get ongoing care and follow your treatment plan as prescribed, try to protect infants and toddlers who have hemophilia from injuries, find out what physical activities are safe for you or your child, and talk to your doctor about what medicines are safe for you.
• Thanks to improvements in treatment, a child who has hemophilia today is likely to live a normal lifespan.