Who should be tested?

Anyone who has atrial fibrillation or deep vein thrombosis, or has had a heart valve replaced. Anyone who has a bleeding disorder or who is taking blood-thinning medicines such as Coumadin.

What is the test for?

To measure the time it takes for blood to coagulate.

Why get tested?

Prothrombin Time, often referred to as a Protime test, is used to monitor the effectiveness of blood-thinning medicines such as Coumadin and to aide in the diagnosis of bleeding disorders. Excessive clotting can block blood vessels and possibly cause a heart attack or stroke. Failure to clot can lead to excessive bleeding or even death.

How is the sample taken?

A blood sample drawn from a vein in the arm.

What do I need to do?

You may need to avoid taking certain medicines before the test because they might affect the test result. Make sure your health care provider knows about any medicines, herbs, or supplements that you are taking. Don't stop any of your regular medicines without first consulting with your health care provider.