Understanding High PT and INR: Causes & Implications

High PT (prothrombin time) and INR (international normalized ratio) indicate that the blood is taking longer to clot than normal. This may be due to a deficiency of clotting factors, which are proteins that help form blood clots. Vitamin K deficiency, liver disease, or the use of blood thinners such as warfarin can all cause prolonged PT and INR. Prolonged PT and INR can be a serious condition if a person starts bleeding, as it can be difficult to stop the bleeding.