Method of detecting coagulation abnormalities in a plasma sample by (a) determining a test rate of thrombin generation over a given time interval by reacting an activator of thrombin with defibrinated normal plasma in the presence of a defibrinated test plasma sample; (b) determining a control rate of thrombin generation over substantially the same time interval in step (a) by reacting the same activator of thrombin with defibrinated normal plasma in the absence of any defibrinated test plasma; and (c) comparing the rates of thrombin generation between test step (a) and control step (b) such that any significant difference between the two thrombin generation rates being indicative of a coagulation abnormality in the test plasma.