What Is Your INR?
INR is the name of the laboratory test used to determine your warfarin (Coumadin®) dose. INR
stands for International Normalized Ratio. This value is a measure of how long it takes your blood
to clot (measured by a prothrombin time or protime test). While taking warfarin, your blood will be
checked regularly to determine if your INR is within your “target” range.
1 = “Normal” bleeding time, not on warfarin.
1.5 = Slight increase in the time it takes your blood to clot; mildly increased
2.0-3.0 = Usual target range for many medical conditions. This is a relatively safe
range with little or no bleeding risks for most patients.
2.5-3.5 = Higher target range used for some medical conditions, such as mechanical
4.0 and above = Increased risk of bleeding. Discuss this result with your health care provider.
Your target INR range is ______________
The reason you are on warfarin is ________________________________________________
Your health care team may have given you this information as part of your care. If so, please use it and call if you
have any questions. If this information was not given to you as part of your care, please check with your doctor. This
is not medical advice. This is not to be used for diagnosis or treatment of any medical condition. Because each
person’s health needs are different, you should talk with your doctor or others on your health care team when using
this information. If you have an emergency, please call 911. Copyright © 7/2015 University of Wisconsin Hospitals
and Clinics Authority. All rights reserved. Produced by the Department of Nursing. HF#5223