Why it's doneBy Mayo Clinic staff
If you take a blood-thinning medication such as warfarin to prevent clots from forming, your doctor will recommend a prothrombin time test to monitor the medication's effectiveness. It can also be ordered to:
- Detect a bleeding disorder
- Diagnose liver problems
- Screen people having surgery for unrecognized bleeding problems
A variation of the prothrombin time test is part of a test series called model for end-stage liver disease (MELD) used to assess the severity and priority of people waiting for liver transplants.
If your doctor suspects you may have liver problems, you may undergo additional testing to assess the health of your liver, such as liver enzyme tests. If your doctor suspects you may have a bleeding disorder, you may undergo additional clotting-function tests.
- PT and INR. Lab Tests Online. http://www.labtestsonline.org/understanding/analytes/pt/glance.html#. Accessed Oct. 3, 2012.
- Prothrombin time. Mayo Medical Laboratories. http://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/9236. Accessed Oct. 3, 2012.
- Feldman M, et al. Sleisenger & Fordtran's Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. 9th ed. Philadelphia, Pa.: Saunders Elsevier; 2010. http://www.mdconsult.com/books/about.do?eid=4-u1.0-B978-1-4160-6189-2..X0001-7--TOP&isbn=978-1-4160-6189-2&about=true&uniqId=229935664-2192. Accessed Oct. 3, 2012.
- Friedman LS. Tests of the liver's biosynthetic capacity (e.g., albumin, coagulation factors, prothrombin time). http://www.uptodate.com/index. Accessed Oct. 3, 2012.