The PT INR test, or Prothrombin Time International Normalized Ratio test, is a medical test used to assess the clotting ability of a patient’s blood. It measures the time it takes for blood to clot and is often used to monitor patients taking anticoagulant medications like warfarin. The results of the test are typically reported as a ratio, with the patient’s PT being compared to a standard value. A higher INR value indicates a longer clotting time and a higher risk of bleeding, while a lower value suggests a shorter clotting time and a higher risk of clot formation. Monitoring PT INR levels is crucial in managing and adjusting medication doses for individuals at risk of clotting disorders or those on anticoagulant therapy.