Prothrombin Time (PT)

Who should get tested for Prothrombin test ?

• The Prothrombin time test evaluates the function of the coagulation factors that are involved in the extrinsic and common pathways.
• Your doctor may order this test for you if you are on blood thinning medication warfarin. In such settings, the prothrombin time is reported as an international normalized ratio also called as INR.
• When people are put on waiting list for liver disease, PT time is one of the many tests used to diagnose the severity of chronic liver diseases.
• Prothrombin time test is one of the many tests used to diagnose bleeding disorders. One test that is frequently ordered along with Prothrombin time is partial thromboplastin time (PTT).

Why Prothrombin test ?

The prothrombin time test along with a partial thromboplastin time (PTT) is a useful test that helps in the diagnosis of unexplained bleeding. It is also used to ascertain the cause behind inappropriate blood clots.

The prothrombin test is used to monitor the effectiveness of blood thinning treatment – warfarin is an anticoagulant that is prescribed to prevent clotting. The dose of warfarin is established basis PT test results. (Warfarin may be prescribed in Deep Vein Thrombosis, patients who have artificial heart valves and patients who have atrial fibrillation)

More about Prothrombin Test:

Reference values for Prothrombin test: 11 – 13.5 seconds

Other names: Prothrombin test, PT, Protime 

Haemostasis is the process that takes part in the body where is an injury and leads to bleeding. There are many clotting factors in the blood which need to present in the correct amounts and need to function correctly for clotting to occur. The process of the formation of a clot is called as the coagulation cascade. Deficiency of coagulation factors leads to excessive bleeding and excessive clotting factors mean there is a risk of excessive clotting.

In a laboratory setting, reagents are added to begin the clotting process and the clotting time is estimated.

Interpretation of Prothrombin test

Your doctor will help interpret the test report for you basis clinical findings.

The prothrombin time estimates the time it takes for the blood to clot. Prothrombin is a protein produced in the liver and helps in the normal clotting process along with many other factors in the blood.