Blood Clotting Efficiency Test - Partial Thromboplastin Time (PTT) Test

The partial thromboplastin time (PTT) test is a blood test that measures the time it takes for a clot to form in a plasma sample after the addition of stimulating agents (partial thromboplastin and calcium). It primarily assesses the efficiency of the intrinsic pathway and the combined pathway factor (factors XII, XI, IX, VIII, X, V, II, and fibrinogen) in the coagulation cascade. It is routinely used to monitor treatment with unfractionated heparin and to detect deficiencies in coagulation factors or the presence of inhibitors (antibodies).