About this test
The Prothrombin Time (PT) test, reported with an INR value, measures how long your blood takes to form a clot. It checks part of the body's clotting system and is widely used to monitor people who take blood-thinning medicines such as warfarin.
Why it is done
- To monitor blood-thinning treatment (warfarin).
- Before surgery or a procedure, to check clotting.
- To look into easy bruising, unusual bleeding or liver problems.
Preparation
No fasting is needed. Please tell us which blood-thinning or other medicines you take. Do not stop any medicine unless your doctor tells you to.
This information is general and is not medical advice. Please speak to your doctor about your results and treatment.