Learn how to pinpoint the cause of prolonged PT / PTT and investigate bleeding in patients with normal PT / PTT. In our last video, we shared the mechanisms behind the PT test. In this video, you will learn the mechanisms behind PTT tests and how to interpret the results. You will be able to formulate a common differential diagnosis of prolonged PTT and know which tests to order next. Demystify hematology and coagulation with our fascinating Hematology & Coagulation Essentials course: http://bit