International normalized ratio (INR)
Prothrombin Time (PT)
Blood platelets collect at the site of the wound in the event of a cut which causes your blood vessel to rupture, creating a temporary plug to stop the bleeding. In order to produce a strong blood clot, a series of 12 plasma proteins, or coagulation “factors” act together to make a substance called fibrin, which seals the wound. However, hemophilia, a bleeding disorder can cause your body to create certain coagulation factors incorrectly, or not at all. Some medications, liver disease, or vitamin K deficiency may cause abnormal clot formation.
If your physician suspects you have a bleeding disorder, he/she may order a PT test to help make a diagnosis. In case you are to undergo a major surgery, your physician may order a PT test to make sure your blood is clotting normally. Regular PT tests may be ordered by your physician if you’re taking the blood-thinning medication warfarin, as too much warfarin can cause excessive bleeding.
Prothrombin, also known as factor II, is just one of many plasma proteins involved in the clotting process. The prothrombin time (PT) test measures the amount of time it takes for your blood plasma to clot.