National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Hemophilia A


Other Names:
Hemophilia, classic; HEM A; Classic hemophilia; Hemophilia, classic; HEM A; Classic hemophilia; Factor 8 deficiency; Factor VIII deficiency; Classical hemophilia; Haemophilia A; Hemophilia A, congenital See More
Categories:
This disease is grouped under:
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]
Last updated: 12/3/2018
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]
Last updated: 12/3/2018

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.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Arthralgia
Joint pain
0002829
Bleeding with minor or no trauma
Easy bleeding
0011889
Joint swelling 0001386
Reduced factor VIII activity 0003125
30%-79% of people have these symptoms
Oral cavity bleeding
Bleeding from mouth
0030140
Spontaneous hematomas 0007420
Thromboembolism 0001907
5%-29% of people have these symptoms
Abnormality of the elbow
Abnormality of the elbows
0009811
Gastrointestinal hemorrhage
Gastrointestinal bleeding
0002239
Intramuscular hematoma 0012233
Intraventricular hemorrhage 0030746
Joint hemorrhage
Bleeding within a joint
Hemarthrosis
[ more ] 		0005261
1%-4% of people have these symptoms
Splenic rupture
Ruptured spleen
0012223
Percent of people who have these symptoms is not available through HPO
Bruising susceptibility
Bruise easily
Easy bruisability
Easy bruising
[ more ] 		0000978
Osteoarthritis
Degenerative joint disease
0002758
Persistent bleeding after trauma
Excessive bleeding after minor trauma
Frequent bleeding with trauma
Prolonged bleeding after minor trauma
[ more ] 		0001934
Prolonged partial thromboplastin time 0003645
X-linked recessive inheritance 0001419
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Last updated: 7/1/2020
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]
Last updated: 12/3/2018
The F8 gene is located on the X-chromosome. Therefore, hemophilia A is inherited in an X-linked recessive pattern.[1][2] In males (who have only one X chromosome), one mutated copy of the F8 gene in each cell is enough to cause hemophilia A. In females (who have two X chromosomes), a mutation needs to occur in both copies of the F8 gene to cause the disorder. Because it is unlikely that females will have two mutated copies of this gene, hemophilia A, like other X-linked recessive disorders, affects males much more frequently than females. Females who have a mutation in one copy of the F8 gene are called carriers. Most carriers have no signs or symptoms, however about 10% of female carriers of hemophilia A will experience some abnormal bleeding.[2] 

A female who carries one F8 gene mutation has a 50% or 1 in 2 chance of having a son with hemophilia A. A male with hemophilia A cannot pass on the disorder to his sons, but all of his daughters will be carriers for hemophilia A.[1] 

When a male child is the first person in a family with hemophilia A, further testing may be needed to determine if the child inherited the disorder from his mother, or if the mutation occurred by chance for the first time in the child.[2]

Last updated: 12/3/2018
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] 
Last updated: 12/3/2018

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]

Last updated: 12/3/2018

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
Hemophilia A can be mild, moderate, or severe, depending on how much clotting factor VIII is in a person's blood. About 50-60% of people with hemophilia A have the severe form of the disorder.[4]

With education and treatment, people with hemophilia A can live healthy and active lives. Life expectancy may depend on the response to treatment and the presence of other health conditions. Life-threatening complications of hemophilia A include bleeding within the skull (intracranial hemorrhage) and bleeding into the soft tissue around important organs. Chronic, debilitating joint disease may also develop.[4]

Last updated: 12/3/2018
About 1/5000 -1/6000 people in the US are born with hemophilia A. This disorder affects males more than females, and occurs equally in all races and ethnic groups.[4][5]
Last updated: 12/3/2018

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
The differential diagnosis should include von Willebrand disease (see this term) and other coagulation anomalies leading to prolonged blood coagulation times.
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Hemophilia A. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

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

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Financial Resources

  • Patient Services, Inc (PSI) provides financial support and guidance for qualified patients with specific chronic diseases. PSI helps patients find solutions to the social and economic problems confronting patients with chronic conditions.

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.
  • Genetics Home Reference (GHR) contains information on Hemophilia A. This website is maintained by the National Library of Medicine.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • 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.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • I have severe hemophilia. How often do genetic mutations for severe hemophilia A occur - in caucasians, in women, and in America?  How common is type A versus type B or other types?  How common is the severe form as opposed to the moderate or mild forms? See answer


  1. Hemophilia. Genetics Home Reference. August, 2012; http://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; http://emedicine.medscape.com/article/779322-overview.
  4. Robert A Zaiden. Hemophilia A. Medscape. November 7, 2014; http://emedicine.medscape.com/article/779322-overview.
  5. Hemophilia A. NORD. Updated 2015; https://rarediseases.org/rare-diseases/hemophilia-a/.