What's a high INR level?

Anything above 1.5. The inr is a measure of how "thin" the blood is, typically due to the use of prescription blood thinners such as Coumadin (warfarin). A normal inr is 1.0. Anything above that is abnormal. For people on coumadin, the typical goal inr is 2.5 to 4.0 depending on the particular condition it is being used for.