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Overview of Clotting Factor VIII
Blood contains different clotting factors which are essential for hemostasis. Hemostasis is the process of clot formation, tissue repair and clot dissolution. Clot formation is important in cases of injuries in order to control bleeding and prevent loss of blood. Dissolution of the clot is also an important process in order to prevent narrowing of the blood vessel due to the presence of the clot. These different clotting factors function by following a pattern known as the coagulation cascade. Each factor plays different roles, mostly leading to the formation of the clot. Deficiency or excess levels of these factors frequently lead to different diseases.
Factor VIII is one of the coagulation factors. A deficiency in the amount of clotting factor VIII in the blood usually result in bleeding tendencies. The most common condition associated with clotting factor VIII deficiency is hemophilia A, an inherited disease affecting males, while affected females are mostly carriers of the disease.
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Diseases Involved with Clotting Factor VIII
As mentioned, hemophilia A is the result of lack of clotting factor VIII in the blood. There are also certain conditions which may result in the increase of clotting factor VIII measurement in the blood. These include inflammatory processes, liver diseases, high blood pressure and diabetes. Old age, pregnancy, smoking and obesity are also associated with increased clotting factor VIII.
A blood test for the assay of clotting factor VIII is frequently done to measure its activity inside the body. Blood is taken through the arm and then processed in the laboratory. Another test which can also indicate the activity of this clotting factor is the partial thromboplastin time (PTT). Other tests generally requested for patients with bleeding disorders also include the prothrombin time (PT), platelet function tests, platelet count, activated clotting time and fibrinogen test.
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Significance of an Elevated Clotting Factor VIII
Elevated amount of clotting factor VIII in the blood may result in different types of blood clotting problems. One example is venous thrombosis which is the formation of clot inside the veins, usually in the leg vein. Complications of venous thrombosis often occur when this blood clot travels to the heart and lodged in the blood vessels of the lungs. When this happens blood flow in the affected organ is blocked often resulting in a life threatening situation known as pulmonary embolism. Symptoms include shortness of breath, chest pains and fainting.
Clot formation in the arteries may also occur. Similar to venous thrombosis, the clot in the arteries can dislodge and travel to different areas of the body. Arteries blocked by clot often fail to deliver oxygen rich blood to the area, thus leading to the manifestation of symptoms such as pain. When vital organs are affected, it may also lead to a life-threatening situation.