T Watson P, MA, B; S Wattley SOC, PS; H Webster MS; J Webster E*, ME*, EL*, H; S White AD; J Whiteley PY, B, C; T Whiteley TT, TH; L Whitley BUS, SOC, MM; O Whittell P, MA, MS; C Whitwam PY, E/EL, ME*; A Whitworth MM; O Widdop PY*, SOC*, E*; C Wilcock PY, EL; M Wilford PY, ME, EL; I Wilinsky EL, PS, H, MM; B Wilkinson AD, ME.
Prothrombin time (PT) Prothrombin time (PT) is a blood test that measures the time it takes for the liquid portion (plasma) of your blood to clot. A related blood test is partial thromboplastin time (PTT). A blood sample is needed. If you are taking ant blood-thinning medicines, you will be watched for signs of bleeding.
The INR comes from the conversion of another value, the prothrombin time (PT). Prothrombin time is the time it takes for blood to clot in a test tube.A high or low PT can suggest bleeding or clotting tendencies. Most often, the PT is checked to monitor a personâs response to blood thinners such as warfarin (Coumadin).he INR comes from the conversion of another value, the prothrombin time (PT). Prothrombin time is the time it takes for blood to clot in a test tube. A high or low PT can suggest bleeding or clotting tendencies.