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Hemophilia is an inherited bleeding disorder. People with hemophilia bleed easily because they don’t have enough of one of the clotting factors in their blood. Clotting factors are needed for blood to clot. Blood clots to prevent excessive bleeding.

There are many blood clotting factors involved in the forming of clots to stop bleeding. The 2 most common clotting factors affected by hemophilia are factor VIII and factor IX.

How severe the hemophilia is depends on the level of blood clotting factors in your blood. The more severe the hemophilia, the less clotting factor is present. The result is higher bleeding risk or more severe hemophilia.

The 3 main forms of hemophilia include:

  • Hemophilia A. This is caused by a lack of or low levels of the blood clotting factor VIII. It is the most common type of hemophilia. About 9 out of 10 people with hemophilia have type A disease. This is also referred to as classic hemophilia or factor VIII deficiency.
  • Hemophilia B. This is caused by a deficiency of or low levels of blood clotting factor IX. This is also called Christmas disease or factor IX deficiency.
  • Hemophilia C. Some healthcare providers use this term to refer to a lack of clotting factor XI. It is a rare condition.


Hemophilia types A and B are inherited, or genetic, diseases. They are passed on from parents to children through a gene on the X chromosome. Females have 2 X chromosomes, while males have 1 X and 1 Y chromosome. This means that boys are at risk for hemophilia, while girls are much more likely to be carriers of the defective gene without symptoms.

  • A female carrier has the hemophilia gene on 1 of her X chromosomes. When a hemophilia carrier female is pregnant, there is a 50/50 chance that the hemophilia gene will be passed on to the baby.
    • If the gene is passed on to a son, he will have the disease.
    • If the gene is passed on to a daughter, she will be a carrier.
  • If the father has hemophilia but the mother does not carry the hemophilia gene, then none of the sons will have hemophilia disease. But all of the daughters will be carriers.

In about 1/3 of the people with hemophilia, there is no family history of the disorder. In these cases, it’s believed that the disorder could be related to a new gene flaw called a mutation.

Carriers of one of the hemophilia genes often have normal levels of clotting factors but may:

  • Bruise easily
  • Bleed more with surgeries and dental work
  • Have frequent nosebleeds
  • Have heavy menstrual bleeding

Carriers of both of the hemophilia genes have the disease called hemophilia with more severe bleeding. They will have a severe decrease in their clotting factors.

Hemophilia C is a problem with factor 11. It usually doesn’t cause spontaneous bleeding. But people may have increased bleeding after surgery.


The most common symptom of this disorder is heavy, uncontrollable bleeding. Bleeding can be external (cuts, nosebleeds) or internal (bruises, joint bleeds).

The severity of hemophilia depends on the amount of clotting factors in the blood. Those affected with hemophilia who have blood clotting factor levels greater than 5% most often have bleeding only with serious injury, major surgeries, or tooth extractions. These people may not even be diagnosed until bleeding complications from a surgery occur.

Severe hemophilia is when the factor VIII or IX levels are less than 1%. Bleeding can occur even with minimal activities of daily life. Bleeding may also occur from no known injury. Bleeding most often occurs in the joints, muscles, and in the head.

Symptoms may include:

  • Bruising. Bruises can occur from even small accidents. This can result in a large buildup of blood under the skin causing swelling (hematoma). Children with hemophilia are often diagnosed around 12 to 18 months of age. This is when the child is more active and bruising becomes more apparent.
  • Easy bleeding. A tendency to bleed from the nose, mouth, and gums with minor injury. Bleeding while brushing and flossing teeth or having dental work is often a sign of hemophilia.
  • Bleeding into a joint (h emarthrosis). This can cause pain, immobility, and deformity if not treated. This is the most common site of complications due to hemophilia bleeding. If joint bleeds keep recurring, they can lead to chronic, painful arthritis and deformity. They can also make it hard to walk or move correctly.
  • Bleeding into the muscles.  Bleeding into the muscles can cause swelling, pain, and redness. Swelling from excessive blood in these areas can increase pressure on tissues and nerves in the area. This can cause permanent damage and deformity.
  • Bleeding in the brain. This can happen from injury or on its own. Bleeding from injury, or spontaneously in the brain, is the most serious bleeding complication and can be life-threatening. Bleeding in or around the brain can occur from even a small bump on the head or a fall. Small bleeds in the brain can result in blindness, intellectual disability, and a variety of neurological deficits. It can lead to death if not spotted and treated right away.
  • Other bleeding. Blood found in the urine or stool may also signal hemophilia. Baby boys born with severe hemophilia may have bleeding after a circumcision that lasts longer than normal.

The symptoms of hemophilia may look like other health problems. Always check with your healthcare provider for a diagnosis.


The diagnosis of hemophilia is based on your family history, your health history, and a physical exam. Blood tests include:

  • Complete blood count (CBC).  A complete blood count checks the red and white blood cells and platelets (clotting cells). In addition to hemophilia, a low platelet count is another cause of bleeding disorders. Your healthcare provider will want to make sure that your platelet count is normal and that a low platelet count is not the cause of your bleeding.
  • Screening tests of clotting times. These are called prothrombin time (PT) and activated partial thromboplastin time (aPTT)
  • Mixing studies with certain clotting factors added. This is done to see if the clotting time (aPTT) corrects. This clarifies if there is a deficiency.
  • Clotting factors levels (also called factor activity levels). This is a test to check the levels of each clotting factor.
  • Genetic or DNA testing. This is done to check for abnormal genes.


Your healthcare provider will refer you or your child to a hematologist, an expert in blood disorders.

Treatment will depend on symptoms, age, and general health. It will also depend on how severe the condition is.

Treatment for hemophilia is aimed at preventing bleeding complications (mainly head and joint bleeds). Treatment may include:

  • Infusion of clotting factor concentrates into a vein. Self-infused factor VIII or IX and other treatment products can help a person with hemophilia lead a typical lifestyle. 
  • Bleeding in the joint may need surgery or immobilization. Rehab of the affected joint may be needed. This may include physical therapy and exercise to strengthen the muscles around the area.
  • Blood transfusions may be needed if major blood loss has occurred. This is when you or your child gets donated blood.


Complications of hemophilia can include:

  • Bleeding in the joints or muscles
  • Inflammation of the joint lining
  • Long-term joint problems
  • Development of antibodies (also called inhibitors) against clotting factors
  • Pain from joint and muscle bleeds
  • Infections from transfusions (HIV and hepatitis B and C are no longer spread through donated blood because of strict testing of the donated blood)

Living with

With careful management and the availability of factor replacement therapy to prevent and treat bleeding, many people with hemophilia can live relatively healthy lives with a normal lifespan.

Managing hemophilia may include:

  • Taking part in activities and exercise, but not ones that may cause injury. Talk with the hematologist about which activities are appropriate.
  • Getting special care before surgery including dental work. Your healthcare provider may advise factor replacement infusions. These increase clotting levels before the procedures. Specific factor replacement infusions during and after the procedure may also be given. These maintain the clotting factor levels and improve healing and prevention of bleeding after the procedure.
  • Preventing dental and gum problems with good dental hygiene.
  • Getting vaccines under the skin instead of in the muscle to prevent bleeding in the muscle. If the vaccine must be given in the muscle, using the smallest gauge needle and putting an ice pack on the skin before and soon after can help.
  • Avoid aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs). They increase bleeding risk.
  • Wearing medical identification (ID) in the case of an emergency.

When to Call a Healthcare Provider

When you should call will vary based on how severe the hemophilia is and what treatment you or your child are getting and is available at home. Since hemophilia is a long-term condition, talk with the healthcare provider about when you should call or get medical care. 

Call your healthcare provider for any of the following:

  • An injury
  • New pain
  • Pain that gets worse
  • Bleeding that you can't control
  • You or your child are scheduled for surgery or another procedure

Key Points

  • Hemophilia is an inherited bleeding disorder. It causes an affected person to have low levels of blood clotting factors.
  • The most common symptom of hemophilia is increased, uncontrollable bleeding.
  • Treatment with factor VIII or IX can allow a person with hemophilia to manage their disorder well and lead a typical lifestyle.

Next Steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
  • Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.
  • Ask if your condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if you do not take the medicine or have the test or procedure.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions, including after hours and on weekends and holidays.

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