The Factor II test is used to determine whether levels of your coagulation factors are increased, normal, or decreased. Coagulation factors are proteins circulating in the blood that are essential for proper blood clot formation. This test can be done when you have unexplained or prolonged bleeding, abnormal results on coagulation screening tests such as prothrombin time (PT) or partial thromboplastin time (PTT), or have a relative with a hereditary coagulation factor deficiency. The test can also be done when your healthcare practitioner wants to monitor the severity of a factor deficiency and/or the effectiveness of treatment.