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What is hemophilia A?
Hemophilia A is a rare genetic bleeding disorder caused by a deficiency of clotting factor VIII. This protein plays a crucial role in the blood clotting process.
In people with hemophilia A, blood does not clot properly, which can lead to prolonged or spontaneous bleeding.
Hemophilia A is the most common type of hemophilia, accounting for approximately 80–85% of all cases.
The condition is usually inherited and linked to the X chromosome, which is why it mainly affects males, while females are often carriers.
With modern treatments and proper medical care, many people living with hemophilia A can lead active and fulfilling lives.
What are the symptoms of hemophilia A?
Symptoms vary depending on the level of factor VIII deficiency.
Common symptoms include:
- prolonged bleeding after injuries or surgery
- frequent bruising
- bleeding into joints (hemarthrosis)
- muscle bleeding
- frequent nosebleeds
In severe cases, spontaneous bleeding episodes may occur.
Repeated bleeding in joints may eventually cause joint damage and chronic pain.
What causes hemophilia A?
Hemophilia A is caused by a mutation in the F8 gene, which provides instructions for producing clotting factor VIII.
Because the gene is located on the X chromosome, the disorder follows an X-linked inheritance pattern.
Men who inherit the mutation develop the disease, while women are usually carriers of the gene.
In some cases, the mutation occurs spontaneously without family history.
How is hemophilia A diagnosed?
Hemophilia A is diagnosed through blood tests that measure clotting factor levels.
These tests usually include:
- measurement of factor VIII activity
- clotting tests
- genetic testing if necessary
Early diagnosis allows doctors to start treatment and prevent complications.
What treatments are available for hemophilia A?
Treatment mainly involves replacing the missing clotting factor VIII.
Two main approaches are used.
On-demand treatment
Factor VIII is given when bleeding occurs.
Preventive treatment (prophylaxis)
Regular infusions of factor VIII help prevent bleeding episodes.
New therapies are also emerging, including:
- extended half-life factor VIII
- bispecific antibodies
- gene therapy
Living with hemophilia A
With proper medical care, many people with hemophilia A can live active lives.
Management typically includes:
- regular follow-up at specialized treatment centers
- learning to recognize bleeding episodes
- engaging in safe physical activity
FAQ about hemophilia A
What is the difference between hemophilia A and B?
Hemophilia A is caused by factor VIII deficiency, while hemophilia B results from factor IX deficiency.
Can hemophilia A be cured?
There is currently no cure, but treatments can effectively manage the condition.
Last updated: 3/5/26
