Your doctor might recommend a prothrombin time test to:
- Monitor the effectiveness of a blood-thinning medication that you're taking
- Diagnose liver problems
- Assess your blood's ability to clot before you have surgery
The prothrombin time test is one of several tests used to screen people waiting for liver transplants. That screening — known as the model for end-stage liver disease (MELD) — is a scoring system for assessing the severity of chronic liver disease.
When you have a prothrombin time test, you might also have:
- Additional testing to assess the health of your liver, if your doctor suspects you have liver problems
- Additional clotting-function tests, if your doctor suspects you have a bleeding disorder