What is an INR test?

If you’re a member of the Zipper Club chances are you have had to get your INR checked. If you’re new to the Zipper Club or will be becoming a member soon, get ready for these important tests. 

When the doctor orders an INR test it means they want to know exactly how well your blood clots.

INR stands for International Normalized Ratio, and these tests also are called PT tests, Pro-Time tests. 

When you take these tests, most often you will get your finger pricked by the nurse and a drop of your blood will be put on a test slide. The slide is inserted into a handheld machine and it will eventually return a number. That number is your INR. 

If you are a high risk patient and you will need to test your INR frequently, chances are you can get your own INR machine through your insurance. I did this a month after my surgery and it has saved me a TON of time, I don’t need to go to the doctors office every time I need to test now.

Another way you can check your INR is by getting your blood drawn by a phlebotomist, but you’ll only do this if you are already in the hospital.


If you are taking a blood thinner your doctor needs to keep an eye on how well your blood clots. If it is too thick there is a chance for complications, and if it is too thin then there is an additional risk of complications.

The number that the INR machine returns will be a value somewhere between 1.0 and 5.0. Your doctor will set a therapeutic range for you which is the range of numbers you want your INR to be in. For most people your therapeutic range will be between 2.0 and 3.0, but it could be slightly higher if you are at a hightened risk of developing clots.

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