Skip to main content
Pharmacology

INR (International Normalized Ratio)

A standardized blood test that measures how slow your blood is clotting on warfarin.

INR is the standardized lab measure of warfarin effect. Most patients on warfarin target an INR of 2.0–3.0; for some indications (mechanical mitral valve), 2.5–3.5.

What this means for you: INR must be in target range before elective surgery; usually <1.5 for major operations. Confirm INR is checked in the days leading up to your procedure.

General information, not medical advice

What a term means for you depends on your own reports. Ask your treating doctor, or send your reports for a free review.

More Pharmacology terms

Want this explained for your case?

Send your reports once. A doctor reviews them and you get written quotes from up to 3 hospitals, free.

Get free quotes Back to the glossary
How this page is made

Methodology and editorial standards

Glossary entries are written by the Medcasts editorial team in plain language and checked against current clinical and regulatory sources.

  1. Hospital data. Accreditation, licences and facilities are checked against public registries (JCI, NABH, health-ministry licence lists) and hospital documents, and rechecked regularly.
  2. Doctor credentials. Qualifications and specialty come from the doctor's hospital profile and national medical council registers.
  3. Prices. Price ranges come from written hospital quotes and packages, not advertised rates.
  4. Clinical text. Written by our editorial team and checked against current published guidelines before it goes live.
  5. Independence. Hospitals cannot pay to change their position on our pages.