What is the normal international normalized ratio (INR) range?

The normal international normalized ratio (INR) range is typically between 0.9 to 1.3 seconds for individuals not on anticoagulant therapy. This range is critical for assessing the coagulation status of patients and guiding anticoagulation therapy. The INR standardizes prothrombin time (PT) results, which may vary between different laboratories due to variations in testing methods and equipment.

When a patient's INR falls within this normal range, it indicates adequate blood clotting function, essential for preventing excessive bleeding during and after surgery, as well as in the general management of bleeding disorders. It is particularly important for healthcare providers to monitor INR closely in patients undergoing anticoagulation therapy to avoid complications related to over or under-coagulation.

The values provided in the other choices represent ranges typically associated with different clinical scenarios. For instance, an INR above 1.3 often indicates the need for further evaluation, especially in patients on anticoagulants, while higher INR levels are used to monitor therapeutic anticoagulant effects.