High INR: Understanding a Blood-Clotting Test

Overview

The international normalized ratio (INR) standardises a prothrombin-time result so clinicians can compare clotting measurements. It is especially important when monitoring warfarin.

How should results or symptoms be assessed?

A higher INR can indicate greater bleeding risk, although the intended target depends on why anticoagulation is prescribed. Liver function, vitamin K intake and medicine interactions may affect it.

Practical next steps

Do not adjust warfarin on your own. Tell the prescribing clinician about new medication, herbal products, major diet changes and any bleeding.

When is medical help needed?

Uncontrolled bleeding, black stools, sudden severe headache or symptoms after a head injury require emergency care.

Frequently asked questions

Can this article establish a diagnosis or treatment?

No. An individual history, examination and sometimes further tests are needed.

What should I prepare for a consultation?

Note when symptoms began, past reports, your medicines and questions so you can discuss them clearly.

Online advice cannot replace an in-person examination when one is required.

This article provides general information and is not individual medical advice.

Reference: https://medlineplus.gov/lab-tests/prothrombin-time-test-and-inr-ptinr/