Liver disease produces coagulopathy through multiple mechanisms including coagulation factor deficiencies, vitamin K deficiency (due to fat malabsorption), dysfibrinogenaemia, thrombocytopaenia and reduced platelet function.

PT/INR does not directly correspond to the true coagulative status of patients with liver disease. Most often these patients are also coagulopathic due to elevated Von Willebrand factor and deficiencies in protein C, protein C, antithrombin and plasminogen.