Hemophilia A is treated with which factor?

Hemophilia A is specifically associated with a deficiency in Factor VIII, which is crucial for proper blood coagulation. The condition leads to prolonged bleeding, as Factor VIII is essential for the clotting cascade to function effectively, allowing platelets to form a stable clot. In patients with Hemophilia A, replacing the missing Factor VIII through infusions is the primary treatment to prevent and control bleeding episodes. This therapy can be administered on-demand during bleeding episodes or as prophylaxis to reduce the frequency of these episodes in patients with severe forms of the disease.

In contrast, Factor IX is relevant to Hemophilia B, von Willebrand Factor (vWF) is important in von Willebrand disease and plays a role in the function of Factor VIII, while Factor X is part of the common pathway in the coagulation cascade but is not specifically the factor that is deficient in Hemophilia A. Thus, Factor VIII is the targeted treatment for this condition, making it the correct answer.