Related Terms

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Background

• Factor XI deficiency is a rare inherited bleeding disorder that occurs when an individual has too little of a protein called factor XI. Factor XI is a clotting factor that plays a key role in the clotting, or coagulation, cascade that is triggered when a blood vessel is damaged. Factor XI may also be called hemophilia C or Rosenthal syndrome. Hemophilia refers to an inherited clotting disorder. There are three types of hemophilia: A, B, and C. Dr. Rosenthal first described Factor XI deficiency in 1953 and originally called it "plasma thromboplastin antecedent deficiency."
• Clotting or coagulation disorders occur when the blood does not form clots properly. Blood clots are clumps of different types of blood cells and proteins called clotting factors that stop bleeding after an injury. The process of blood clotting is called coagulation or hemostasis.
• When a blood vessel breaks due to an injury or surgical incision, it narrows to slow blood flow so that clotting can begin. At the same time, the blood that has leaked outside of the injured blood vessel presses against the vessel to help prevent further blood loss. Blood cells called platelets are activated to move toward the site of injury. Once platelets reach the site of injury, a series of reactions started by enzymes called coagulation factors lead to the activation of a protein called thrombin. Factor XI is one of the coagulation factors. These factors convert a blood clotting factor, fibrinogen, into long strands that form a net around the platelets and blood cells to help trap more platelets to form a blood clot.
• The blood clot, called a thrombus, is a temporary plug to control bleeding. Once the platelets are clumped together, they become activated and stick together. Sometimes blood clots are visible and appear as bruises under the skin or scabs on the skin. Once the blood vessel is healed, other blood factors are released to destroy the clot by dissolving it into the blood.
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Risk Factors

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Causes

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Signs and Symptoms

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Diagnosis

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Complications

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Treatment

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Integrative Therapies

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Prevention

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Author Information

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References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

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