Activated Partial Thromboplastin Time (APTT) Test

The Activated Partial Thromboplastin Time (APTT) test measures the time it takes for blood to clot. It evaluates the function of clotting factors in the intrinsic and common pathways of the coagulation system. This test is primarily used to diagnose bleeding disorders, monitor patients on heparin therapy, and assess overall blood clotting function.

An increased APTT time may indicate conditions such as hemophilia, liver disease, Vitamin K deficiency, or the presence of anticoagulants (e.g., lupus anticoagulant). A shortened APTT is less common but may suggest excessive clotting activity. Doctors often recommend this test for individuals with unexplained bleeding, bruising, or before surgery to assess clotting function. It is also performed alongside other coagulation tests, such as Prothrombin Time (PT) and D-Dimer, for a comprehensive evaluation.