PTT stands for partial thromboplastin time and it is the test that measures the time it takes for blood to clot in a blood sample.
It is a performance indicator measuring the efficacy of both the intrinsic and the common coagulation pathways.
PTT is also used to monitor the treatment effects with heparin a major anticoagulant.
An abnormal PTT result may also be due to bleeding disorders (like Haemophilia) or a group of conditions in which there is a problem with the body's blood clotting process.