Prothrombin Time with INR Test

The Prothrombin Time (PT) with International Normalized Ratio (INR) Test measures how quickly blood clots by evaluating the extrinsic and common coagulation pathways. The PT result is reported in seconds, while the INR provides a standardized value that allows results to be compared across laboratories. This test is commonly used to assess bleeding or clotting disorders, evaluate liver function, monitor warfarin (Coumadin®) therapy, and detect deficiencies in vitamin K or clotting factors. Abnormal PT or INR results may indicate impaired blood clotting, liver disease, anticoagulant effects, or other conditions affecting the body’s ability to form stable blood clots.