A PT/INR test measures how long it takes your blood to clot and helps evaluate the clotting ability of your body. PT (Prothrombin Time) checks the time required for blood to clot, while INR standardizes the result so it can be compared across different laboratories. This test is commonly recommended for patients taking blood-thinning medications like warfarin, or when doctors suspect liver disease, vitamin K deficiency, or clotting disorders.

For the PT/INR test, a small blood sample is collected from a vein, and fasting is usually not required unless advised by your doctor. The test is essential for monitoring anticoagulant therapy, ensuring the medication dosage is safe and effective, and preventing complications such as excessive bleeding or blood clots.