Prothrombin Ratio (INR)
The INR is a standardised test looking at how you blood clots. It is most commonly used to monitor warfarin therapy ( a blood thinner) but can also be used to assess patients with liver failure , detect vitamin K deficiency , investigate bleeding disorders or screen patients before surgery looking at their clotting system.
Test details
Sample type
Blood
Time of day
No specific time required
Fasting required
No
Results timeframe
Within 7 days
Preparation
No special preparation required
What's measured in this test
INR Prothrombin Ratio
Monitors blood clotting time.
Common reasons for testing
- Monitoring anticoagulant therapy – Regular assessment of INR levels to ensure effective and safe dosing of medications like warfarin.
- Evaluating liver function – Since clotting factors are produced in the liver, this test can help assess hepatic health.
- Investigating bleeding disorders – Identifies potential clotting abnormalities that may lead to excessive bleeding or thrombosis.