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Disease Profile

Hemophilia A

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

1-9 / 100 000

US Estimated

Europe Estimated

Age of onset






Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Hemophilia, classic; HEM A; Classic hemophilia;


Blood Diseases


Hemophilia A is an inherited bleeding disorder in which the blood does not clot normally.[1][2][3] People with hemophilia A will bleed more than normal after an injury, surgery, or dental procedure. This disorder can be severe, moderate, or mild. In severe cases, heavy bleeding occurs after minor injury or even when there is no injury (spontaneous bleeding). Bleeding into the joints, muscles, brain, or organs can cause pain and other serious complications. In milder forms, there is no spontaneous bleeding, and the disorder might only be diagnosed after a surgery or serious injury. Hemophilia A is caused by having low levels of a protein called factor VIII. Factor VIII is needed to form blood clots. The disorder is inherited in an X-linked recessive manner and is caused by changes (mutations) in the F8 gene.[1][2] The diagnosis of hemophilia A is made through clinical symptoms and specific laboratory tests to measure the amount of clotting factors in the blood. The main treatment is replacement therapy, during which clotting factor VIII is dripped or injected slowly into a vein.[2][3] Hemophilia A mainly affects males. With treatment, most people with this disorder do well. Some people with severe hemophilia A may have a shortened lifespan due to the presence of other health conditions and rare complications of the disorder.[3]


The symptoms of hemophilia A and the age symptoms appear vary depending on the amount of factor VIII a person’s body makes. Infants with the severe form may bleed abnormally from their mouth and develop ‘goose eggs’ on their heads (collections of blood under the scalp). Other symptoms of the severe form include bleeding without any known cause (spontaneous bleeding) into the muscles, joints, and organs. Children with the moderate form may bruise easily and bleed too much after minor injuries, dental work, or surgery. People with the mild form of hemophilia A may not be diagnosed until they bleed more than normal after a major injury or surgery. With the mild form, there are no episodes of spontaneous bleeds.[1][2]

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Joint pain
Bleeding with minor or no trauma
Easy bleeding
Joint swelling
Reduced factor VIII activity
30%-79% of people have these symptoms
Oral cavity bleeding
Bleeding from mouth
Spontaneous hematomas
5%-29% of people have these symptoms
Abnormality of the elbow
Abnormality of the elbows
Gastrointestinal hemorrhage
Gastrointestinal bleeding
Intramuscular hematoma
Intraventricular hemorrhage
Joint hemorrhage
Bleeding within a joint

[ more ]

1%-4% of people have these symptoms
Splenic rupture
Ruptured spleen
Percent of people who have these symptoms is not available through HPO
Bruising susceptibility
Bruise easily
Easy bruisability
Easy bruising

[ more ]

Degenerative joint disease
Persistent bleeding after trauma
Excessive bleeding after minor trauma
Frequent bleeding with trauma
Prolonged bleeding after minor trauma

[ more ]

Prolonged partial thromboplastin time
X-linked recessive inheritance


Hemophilia A is caused by genetic changes (mutations) in the F8 gene. This gene is responsible for making the Factor VIII protein, an important protein that helps start the formation of blood clots. Mutations in the F8 gene lead to reduced or absent levels of Factor VIII in the blood, making it hard for the body to form blood clots.[1][2]


The diagnosis of hemophilia A is made through the clinical symptoms and confirmed by laboratory testing. Blood tests are done to measure the time it takes the blood to clot and the amount of clotting factors found in the blood.[4] Genetic testing can also help determine the exact change in the F8 gene and can be helpful for identifying other family members at risk for hemophilia A.[2]

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.


    People with inherited hemophilia A require life-long care, preferably through a specialized hemophilia treatment center.[2][4] These centers are located around the United States and can be found through the Centers for Disease Control and Prevention. The National Hemophilia Foundation has links to management and treatment guidelines.

    There is no cure for hemophilia A, but current treatments can prevent many of the symptoms of hemophilia A[4]. Treatment may include medications and replacing the missing clotting factor (replacement therapy). This type of replacement therapy is done by slowly injecting or dripping concentrated factor VIII into a vein (intravenous infusion). The type and frequency of treatment often depends on the severity of the disorder in each person.[2][5]

    People with mild or moderate hemophilia A may be treated with replacement therapy as needed (for example, when a bleeding episode occurs). This is called ‘on-demand’ therapy. Some people with mild hemophilia A may be treated with desmopressin (DDAVP).[2][4] Desmopressin raises the levels of factor VIII in the blood and may be given directly into a vein or through a nasal spray. Drugs known as antifibrinolytics, which slow the breakdown of clotting factors in the blood, can also be used to treat a mild form of the disorder.[4]

    Some people with severe hemophilia A may receive regular factor VIII replacement therapy to prevent bleeding episodes and other complications such as joint damage. This is referred to as prophylactic or preventative therapy. These factor VIII infusions may be done as often as necessary depending on the severity.[2][4] The immune system of some people with the severe form of hemophilia A may start to make antibodies (inhibitors) that prevent the replacement factor VIII from working.[4][5] Treatment for these people includes larger doses of replacement factor VIII and/or medications that may help block the inhibitors.[5]

    Infusions of replacement Factor VIII can be given at home. This is especially important for people with severe disease because the infusion works the best within one hour of a bleeding episode. In general, prompt treatment is important because it reduces pain and damage to the joints, muscles, or other affected tissues or organs.[4]

    FDA-Approved Treatments

    The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.

    • Antihemophilic factor (recombinant), Fc fusion protein(Brand name: Eloctate) Manufactured by Bioverativ, a Sanofi Company
      FDA-approved indication: November 2010, antihemophilic factor (recombinant), Fc fusion protein (Eloctate) was approved for the treatment of adults and children with Hemophilia A (congenital Factor VIII deficiency) for control and prevention of bleeding episodes, perioperative management, and routine prophylaxis to prevent or reduce the frequency of bleeding episodes.
      National Library of Medicine Drug Information Portal
    • Emicizumab-kxwh(Brand name: Hemlibra) Manufactured by Genentech
      FDA-approved indication: October 2018, emicizumab-kxwh (Hemilibra) received expanded approval for the routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients ages newborn and older with hemophilia A (congenital factor VIII deficiency) without factor VIII inhibitors. In November 2017, it was approved for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients with hemophilia A (congenital factor VIII deficiency) with factor VIII inhibitors.
      National Library of Medicine Drug Information Portal
    • Antihemophilic factor (recombinant)(Brand name: Kogenate FS) Manufactured by Bayer Corporation
      FDA-approved indication: June 2000, Kogenate FS was approved for the treatment and prophylaxis of bleeding in patients with hemophilia A (not von Willebrand's disease).
      National Library of Medicine Drug Information Portal
    • Coagulation Factor VIIa (Recombinant)(Brand name: NovoSeven RT) Manufactured by Novo Nordisk, Inc.
      FDA-approved indication: March 2005, NovoSeven RT was approved for the prevention of bleeding in surgical interventions or invasive procedures in hemophilia A or B patients with inhibitors to Factor VIII or Factor IX. Previously in March 1999, NovoSeven RT was approved for the treatment of bleeding episodes in hemophilia A or B patients with inhibitors to Factor VIII or Factor IX. July 2014, NovoSeven RT was approved for the treatment of bleeding episodes and peri-operative management in adults and children with Glanzmann's thrombasthenia with refractoriness to platelet transfusions, with or without antibodies to platelets.
      National Library of Medicine Drug Information Portal
    • Moroctocog alfa(Brand name: ReFacto) Manufactured by Pfizer
      FDA-approved indication: March 2000, moroctocog alfa (ReFacto) was approved for the control and prevention of hemorrhagic episodes and for surgical prophylaxis in patients with hemophilia A (congenital factor VIII deficiency or classic hemophilia).
      National Library of Medicine Drug Information Portal
    • Desmopressin acetate(Brand name: Stimate) Manufactured by CSL Behring, LLC
      FDA-approved indication: March 1994, desmopressin acetate (Stimate) was approved for the treatment of patients with hemophilia A or von Willebrand's disease (type I) whose factor VIII coagulant activity level is greater than 5%.
      National Library of Medicine Drug Information Portal
      Medline Plus Health Information


    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Supporting this Disease

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

      • The American Society of Gene & Cell Therapy provides information on the treatment of hemophilia.
      • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
      • Genetics Home Reference (GHR) contains information on Hemophilia A. This website is maintained by the National Library of Medicine.
      • The Merck Manuals Online Medical Library provides information on this condition for patients and caregivers.
      • The National Heart, Lung, and Blood Institute (NHLBI) has information on this topic. NHLBI is part of the National Institutes of Health and supports research, training, and education for the prevention and treatment of heart, lung, and blood diseases.
      • The National Human Genome Research Institute's (NHGRI) website has an information page on this topic. NHGRI is part of the National Institutes of Health and supports research on the structure and function of the human genome and its role in health and disease.
      • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

        In-Depth Information

        • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
        • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Hemophilia A. Click on the link to view a sample search on this topic.


          1. Hemophilia. Genetics Home Reference. August, 2012; https://ghr.nlm.nih.gov/condition/hemophilia. Accessed 11/19/2018.
          2. Konkle BA, Huston H, Fletcher SN. Hemophilia A. GeneReviews. June 22, 2017; https://www.ncbi.nlm.nih.gov/books/NBK1404/.
          3. Drelich DA. Hemophilia A. Medscape Reference. Sept 10, 2018; https://emedicine.medscape.com/article/779322-overview.
          4. Robert A Zaiden. Hemophilia A. Medscape. November 7, 2014; https://emedicine.medscape.com/article/779322-overview.
          5. Hemophilia A. NORD. Updated 2015; https://rarediseases.org/rare-diseases/hemophilia-a/.

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