Partial Thromboplastin Time (PTT) The partial thromboplastin time (PTT) exam also measures the velocity of clotting but differs from the PT examination in that it aims to ascertain how blood clots within a blood vessel (intrinsic pathway). When you have an autoimmune condition like lupus or antiphospholipid syndrome (APS) that https://okaydirectory.com/listings13033091/the-greatest-guide-to-%E4%B9%9D%E5%B7%9E%E5%A8%9B%E6%A8%82