Partial Thromboplastin Time, Activated
- aPTT (Activated Partial Thromboplastin Time)
Thromboplastin is a blood component necessary for normal blood clotting. PTT measures the amount of time it takes for a blood sample to clot. Longer clotting times are seen in people with inherited blood disorders or diseases such as Hemophilia A or Hemophilia B, vitamin K deficiency, liver disease, or diseases that decrease the amount of nutrients absorbed from the diet. PTT is usually measured to determine the cause of abnormal formation of blood clots, but will also be done to monitor the effectiveness of blood-thinners such as heparin or Coumadin (warfarin) that are given as a treatment to prevent the formation of excessive blood clots. Shortened clotting times are also seen in people who are just beginning to develop DIC (disseminated intravascular coagulation) or with wide-spread cancer. Prolonged clotting times are seen in people with fully developed DIC, vitamin K deficiency, cirrhosis, inherited blood-clotting diseases, or while receiving heparin therapy.
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