The most common uses for a PT/INR test are to:
- Check to see how well warfarin is working for you. Warfarin is a blood thinner that is used to treat and prevent life-threatening blood clots. (Warfarin is marketed under the brand name Coumadin.)
- Find out why your blood clots are abnormal.
- Find out what's causing the unusual bleeding.
- Before surgery, make sure your clotting function is in good working order.
- Examine your liver for any issues.
- A partial thromboplastin time (PTT) test is frequently performed in conjunction with a PT/INR test. A PTT test looks for clotting issues as well.