Normal INR Levels. The normal range for a healthy person not using warfarin is 0.8–1.2. However, this is a dangerously low INR for a person using Warfarin.
In healthy people an INR of 1.1 or below is considered normal. An INR range of 2.0 to 3.0 is generally an effective therapeutic range for people taking warfarin for disorders such as atrial fibrillation or a blood clot in the leg or lung. In certain situations, such as having a mechanical heart valve, you might need a slightly higher INR.
Normal international normalized ratio, or INR, levels for individuals who are not on anticoagulant medication range between 0.9 and 1.1. Patients who are on blood thinning medications typically have elevated INR levels between 2 and 3.5, according to the American Association for Clinical Chemistry.
A prothrombin time test tells you how long it takes your blood to clot. Learn what it looks for, when you might need one, and what the results mean.
The international normalised ratio (INR) is a laboratory measurement of how long it takes blood to form a clot. It is used to determine the effects of oral anticoagulants on the clotting system. Devised in 1983, the INR provides a standardised method of reporting the effects of an oral anticoagulant such as warfarin on blood clotting.
The prothrombin time (PT) is a test used to help diagnose bleeding or clotting disorders. The international normalized ratio (INR) is a calculation based on results of a PT that is used to monitor treatment with the blood-thinning medication warfarin (Coumadin®).
The international normalized ratio (INR) is a standardized number that's figured out in the lab. If you take blood thinners, also called anti-clotting medicines or anticoagulants, it's especially important to check your INR. The INR is figured out using the results of the prothrombin time (PT) test.
The prothrombin ratio (aka international normalized ratio) is the prothrombin time for a patient sample divided by the result for control plasma.  International normalized ratio. The result (in seconds) for a prothrombin time performed on a normal individual will vary according to the type of analytical system employed.
If you are not taking blood thinning medicines, such as warfarin, an INR result above 1.1 means your blood is clotting more slowly than normal. This may be due to: Bleeding disorders, a group of conditions in which there is a problem with the body's blood clotting process. Disorder in which the proteins that control blood clotting become over active (disseminated intravascular coagulation).
PT INR normal values are important figures that help doctors determine the ability of a person’s blood to clot. The standard values of PT INR may vary from lab to lab, and so it is very important to have the PT INR results interpreted by qualified physician.