Share this page
Print this article
Was this page helpful?

PT

Also known as: Prothrombin Time; Pro Time
Formal name: Prothrombin Time
Related tests: Activated Clotting Time (ACT), Activated Partial Thromboplastin Time (aPTT or PTT), Prothrombin Consumption Time (PCT), Fibrinogen, Coagulation Factors

The Test Sample

What is being tested?

The test measures how long it takes for your blood to begin to form clots. Prothrombin is a plasma protein produced by the liver. Clotting is caused by a series of chemical reactions, including the conversion of prothrombin to thrombin. The test used to measure this clotting factor is called Prothrombin time, Pro time or PT.

How is the sample collected for testing?

Blood is collected by needle from a vein in the arm.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.