Prothrombin time (PT)PT; Pro-time; Anticoagulant-prothrombin time; Clotting time: protime; INR; International normalized ratio
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).
Chernecky CC, Berger BJ. Prothrombin time (PT) and international normalized ratio (INR) - blood. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. St Louis, MO: Elsevier Saunders; 2013:930-935.
Ortel TL. Antithrombotic therapy. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St Louis, MO: Elsevier; 2017:chap 42.