KidsMD Health Topics

Pediatric Hemophilia

  • Hemophilia is an inherited bleeding disorder in which the blood does not clot normally due to a lack of clotting protein. People with hemophilia bleed for a longer time than others after an injury.

    • Hemophilia is passed from parents to children through genes.
    • Approximately one out of every 5,000 boys born has hemophilia.
    • Hemophilia affects all races equally.
    • People with hemophilia A have absent or low levels of clotting factor VIII (8).
    • People with hemophilia B have absent or low levels of clotting factor IX (9).
    • Hemophilia can be mild, moderate or severe, depending on the level of clotting protein in the blood.
    • There are many available treatment options for hemophilia to help prevent complications associated with excessive bleeding.

    How Boston Children's Hospital approaches hemophilia

    Children with hemophilia receive treatment at the Boston Hemophilia Center, the largest hemophilia program in New England.

    • The Boston Hemophilia Center is a joint program between Dana-Farber/Boston Children's Cancer and Blood Disorders Center and Brigham and Women's Hospital. Pediatric patients are seen at Dana-Farber/Boston Children's; adults are seen at Brigham and Women's Hospital.
    • Our comprehensive care model ensures that every aspect of your child’s health is monitored by experienced pediatric caregivers.
    • Our goal is to enable children with hemophilia and their families to manage the illness as independently as possible and therefore lead more normal, healthy lives.

    Reviewed by Kapil Saxena, MD, and Ellis Neufeld, MD, PhD © Boston Children’s Hospital 2013

  • What causes hemophilia? 

    Normal blood contains a number of different proteins called “factors” that help form clots and stop bleeding. If one of these factors is lacking or defective, the blood cannot clot properly, potentially resulting in a bleeding disorder.

    The two main types of hemophilia are hemophilia A and hemophilia B.

    Hemophilia A is caused by an abnormally low level of factor VIII.

    Hemophilia B is caused by an abnormally low level of factor IX.

    • Normal plasma levels of factor VIII and IX range from 50% to 150%.
    • Hemophilia can be mild, moderate or severe, depending on the factor level.
    • People with severe hemophilia have <1% of factor in their blood.

    Hemophilia A and B are inherited disorders passed from mother to child through the X-chromosome. Males have one X and one Y chromosome (XY), while females have two X chromosomes (XX). A male who carries the hemophilia gene on his X chromosome has hemophilia. A female who carries the hemophilia gene on one of her X chromosomes is a “carrier.” A person can have either hemophilia A or B, but not both.

    About one-third of children with hemophilia have no family history of the disease and their hemophilia is due to a new genetic mutation.


    What are the symptoms of hemophilia?

    The most common symptoms of hemophilia in children are excessive bleeding and easy bruising. Children with hemophilia don’t bleed faster than normal, they bleed for a longer time because their blood clots slowly. The extent of bleeding depends on the severity of hemophilia. Children with mild hemophilia may have no bleeding episodes unless they have excessive bleeding from trauma or a dental procedure or surgery. Children with severe hemophilia get spontaneous joint bleeds.

    Symptoms of hemophilia in children may include:

    • Bruises from small accidents, which may result in large hematomas (collection of blood under the skin that cause swelling)
    • Nosebleeds
    • Bleeding in the mouth or gums from minor trauma or while brushing teeth
    • Blood in the urine or stool
    • Muscle bleeds causing pain and swelling
    • Joint bleeds causing pain, swelling and immobility
    • Internal bleeding such as head bleed, which can be life-threatening

    When to see a doctor

    You should call your doctor immediately if you notice any of the above symptoms.

  • How is hemophilia diagnosed?

    If your child is thought to have hemophilia, he or she will be referred to a hematologist (a doctor with specialized training in treating blood disorders) for a clotting factor test. This test determines the levels of factors VIII and IX in the blood.


  • How is hemophilia treated?

    Treatment of hemophilia depends on the type and severity, with the goal of preventing complications associated with excessive bleeding. Factor replacement therapy is the standard of care.

    Your child will require factor replacement therapy—infusions (injections into a vein) of clotting factors VIII or IX—which can prevent or stop bleeding and promote healing. These infusions will be needed:

    • after a bleeding episode
    • before, during or after surgery and routine procedures, including dental work
    • as a preventive measure (prophylaxis) in the case of severe hemophilia

    Factor replacement therapy stops bleeding and reduces the risk of complications. Children receive infusions of synthetic clotting factors to replace the factors missing from their blood. Children with hemophilia A receive factor VIII infusions, while patients with hemophilia B receive factor IX infusions.

    If your child has mild hemophilia A, he may also receive a synthetic hormone called desmopressin, or DDAVP. This can be administered as a nasal spray or intravenously (through an IV).

    Some patients may develop an inhibitor to clotting proteins and will require hemophilia treatment with other clotting proteins, such as activated factor VII.

    During the course of treating the hemophilia, your child’s doctor will recommend:

    • giving routine immunizations subcutaneously (under the skin) in the muscle to prevent deep muscle bleeds―this is important for your pediatrician to know
    • avoiding aspirin and ibuprofen, as well as products containing them, since they have been linked to bleeding problems
    • getting frequent follow-up care, including regular assessment of the joints; children who experience bleeding into the joints may require physical therapy

    Find in-depth information on pediatric hemophilia treatment on our Boston Hemophilia Center page.

  • The Boston Hemophilia Center is dedicated to advancing understanding and treatment of hemophilia and other bleeding disorders.

    • We currently offer several active clinical research studies available to children with these conditions.
    • Our scientists are also currently conducting research that we hope will help to improve the lifestyle of our patients, including trials of new, longer-acting replacement factors aimed at reducing the frequency of required treatments.
    • In addition, we are investigating the possible use of gene therapy to treat hemophilia and other bleeding disorders.

    Learn more about our research.

    Clinical Trials

    For many children with rare or hard-to-treat conditions, clinical trials provide new options.

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Dana-Farber/Boston Children's Cancer and Blood Disorders Center

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