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).

How the Test is Performed

How to Prepare for the Test

How the Test will Feel

Why the Test is Performed

Normal Results

What Abnormal Results Mean

Risks