Q: What is hemophilia?1
A: Hemophilia is a rare disorder in which a person's blood does not clot properly because the body does not produce enough of, or is missing, the blood clotting proteins, factor VIII, factor IX, or factor XI. Your body depends on these clotting factors to stop bleeding after injury and to promote clotting.
As a person with hemophilia, you bleed longer than someone without hemophilia when you get a cut or bleed internally. Internal bleeding is usually into joints and muscles, but can also occur in the brain or other organs.
Q: What are the types of hemophilia?1
A: Hemophilia A, also called classic hemophilia, occurs when clotting factor VIII is either absent or not present in sufficient amounts.
Hemophilia B, also called Christmas disease, occurs when clotting factor IX is either absent or not present in sufficient amounts.
Hemophilia C, also called plasma thromoplastin antecedent (PTA) deficiency, occurs when clotting factor XI is either absent or not present in sufficient amounts.4
Cases of each type can be mild, moderate or severe, depending on the level and type of protein deficiency.
Q: Who has hemophilia?
A: Hemophilia primarily affects males. The incidence of hemophilia A is one in 5,000 live male births.2
Hemophilia A is more common than hemophilia B. The incidence of hemophilia B is one in 25,000 births in the U.S., mostly males.3
Hemophilia C occurs in one out of every 100,000 births. It can occur with greater frequency in people who are of Jewish or Eastern European ancestry. Also, unlike hemophilia A and B, the rates of this condition are equal among men and women.4
Q: What are the levels of severity of hemophilia?2,3
A: The severity of hemophilia is dependent on the amount of clotting factor that is either missing or deficient.
Mild hemophilia patients have factor VIII levels 6 to 49% or factor IX levels 5% to 50% of normal.
Moderate hemophilia patients have factor VIII levels or factor IX levels of 1% to 5% of normal.
Severe hemophilia patients have factor VIII levels or factor IX levels of < 1% of normal.
Q: How does blood clot?5,7
A: Bleeding causes a biological "domino effect" in which a series of steps are set in motion. Blood vessels begin to shrink to reduce blood flow. Then, platelets (blood-clotting cells) begin to collect at the injured site to form a temporary plug.
In the meantime, clotting factor proteins are sequentially activated in the blood clotting cascade to form a fibrin clot at the wound site, stopping the bleed. For more information, see The Way Blood Clots.
For people with hemophilia, the missing proteins prevent the domino effect from completing. As a result, your clotting process takes longer to begin without treatment.
Q: What are clotting factors?5,7
A: Clotting factors are proteins found in blood that work together to make a blood clot. They are designated by Roman numerals I through XIII.
When the body detects bleeding, clotting factors are switched on in sequential order, each activating the next factor in the blood-clotting cascade to ultimately form a fibrin clot. The fibrin acts like a net that holds the platelets together to make a firm blood clot.
Factor VIII and factor IX are some of the clotting factor proteins that help produce the fibrin clot. In persons with hemophilia, whose bodies do not make sufficient clotting factor, fibrin is not made properly, so firm blood clots do not form in the wound and bleeding is not easily stopped.
Q: Can hemophilia be cured?6
A: There is presently no cure for hemophilia, but with proper treatment using clotting factors, everyone, even people with rare and severe hemophilia, can enjoy their life.
Q: What are the treatment options for people with hemophilia?6
A: Factor replacement therapy works by replacing the missing or nonfunctioning clotting protein.
When clotting factor is administered after an injury, the body begins to use it immediately to form a clot. This therapy is not a cure for hemophilia – it's a temporary replacement therapy used to treat symptoms of hemophilia. Prophylaxis can help hemophilia patients protect against injury.
In people without hemophilia, clotting factor is continuously used and remade by the body.
Q: What are inhibitors?1
A: Inhibitors are antibodies that are made by our immune system. In general, when your immune system identifies a foreign substance, it makes antibodies that will specifically recognize that substance and destroy it to defend you from harmful diseases.
In some individuals with hemophilia, the factor replacement therapy is identified as a foreign substance by their immune system. If this happens, the immune system will make antibodies against factor. These antibodies will inhibit the ability of the infused factor to work in the clotting process. This can seriously complicate the treatment of a bleed.
The good news is that there are different treatment options available to help manage bleeding episodes in hemophilia patients who develop inhibitors.
Q: Where can I get more information about hemophilia?
A: Baxter's Nava is designed to help you navigate your life with hemophilia. Baxter's NAVA contains a wealth of information and resources related to all aspects of living with and caring for someone with hemophilia. Visit Bleeding Disorder Organizations to find organizations and websites that specialize in hemophilia.
Nava.baxter.com does not recommend a particular treatment for specific individuals and recommends that you consult your treatment center or physician before pursuing any course of treatment.
- Frequently Asked Questions About Hemophilia. World Federation of Hemophilia website. http://www.wfh.org/en/page.aspx?pid=637. Accessed April 24, 2014.
- Hemophilia A (factor VIII Deficiency). National Hemophilia Foundation website. http://www.hemophilia.org/NHFWeb/MainPgs/MainNHF.aspx?menuid=180&contentid=45&rptname=bleeding. Accessed April 24, 2014.
- Hemophilia B (factor IX). National Hemophilia Foundation website. http://www.hemophilia.org/NHFWeb/MainPgs/MainNHF.aspx?menuid=181&contentid=46&rptname=bleeding. Accessed April 24, 2014.
- Factor XI Deficiency. National Hemophilia Foundation website. http://www.hemophilia.org/NHFWeb/MainPgs/MainNHF.aspx?menuid=189&contentid=54&rptname=bleeding. Accessed April 24, 2014.
- What are rare clotting factor deficiencies? World Federation of Hemophilia website. http://www.wfh.org/en/page.aspx?pid=662. Accessed April 24, 2014.
- What Is Hemophilia? World Federation of Hemophilia website. http://www.wfh.org/en/page.aspx?pid=646. Accessed April 24, 2014.
- World Federation of Hemophilia. The clotting process. http://www.wfh.org/en/page.aspx?pid=635. Accessed April 24, 2014.
- Frequently asked questions. World Federation of Hemophilia. www.wfh.org/en/page.aspx?pid=637#Pure. Accessed May 22, 2014.