MedFast.AI

Clotting

INR

Also known as: Prothrombin Time Ratio, PT-INR

What it means

Measures how quickly your blood clots. Patients on blood-thinners (Warfarin/Acitrom) monitor this monthly. Higher = thinner blood.

Typical normal range

Off medication: 0.8–1.1 · On Warfarin: 2.0–3.0

Reference ranges vary by lab, age, sex, and pregnancy. Always check the range on your own report.

Have INR on your report?

Upload the full report and MedFast.AI will explain every value — in your language — and give you the right questions to ask your doctor.

Related terms in Clotting

This is a plain-language explanation for patients, not clinical advice. AI can be wrong. Always confirm with your doctor.