Disseminated intravascular coagulation (DIC) is characterized by which process?

• A. Prothrombin deficiency
• B. Platelet function disorder
• C. Disseminated intravascular coagulation (pathological activation of coag cascade)
• D. Hemophilia A

Answer: (C)

A basic idea being tested is that DIC is defined by abnormal, systemic activation of the coagulation system, not just a single-factor problem. In DIC the coagulation cascade is inappropriately turned on throughout the small vessels, forming fibrin clots (microthrombi) all over the circulation. As this process uses up platelets and clotting factors, levels fall, so the patient can simultaneously develop widespread bleeding—this is a consumption coagulopathy. DIC often follows severe illness or injury, such as sepsis, obstetric emergencies, trauma, or cancer, and labs typically show prolonged PT and aPTT, low fibrinogen, thrombocytopenia, and elevated D-dimer.

Why this choice fits best: it captures that DIC is driven by pathological activation of coagulation leading to widespread clot formation and consumption of clotting components, rather than a simple deficiency of a single factor, a primary platelet disorder, or a single-factor bleeding condition like Hemophilia A.