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Also known as: Partial Thromboplastin Time; PTT; Kaolin Cephalin Clotting Time (KCCT)
Formal name: Activated Partial Thromboplastin Time (aPTT)

At a Glance

Why Get Tested?

As part of an investigation of a bleeding or thrombotic episode. To help evaluate your risk of excessive bleeding prior to a surgical procedure although numerous studies have shown that it cannot accurately estimate risk of bleeding in all patients. To monitor unfractionated heparin anticoagulant therapy

When to Get Tested?

When you have unexplained bleeding or thrombosis (a blood clot). When you are on unfractionated or intravenous (IV) heparin anticoagulant therapy. Sometimes as part of a pre-surgical screen

Sample Required?

A blood sample is taken by needle from a vein in the arm

Test Preparation Needed?