Coagulation

INR

INR measures how quickly the blood clots via the extrinsic pathway — standardized across laboratories. It is used mainly to monitor the medication warfarin (blood thinning) and to assess liver function.

Ranges we useISTH (metoda)
RatingRangeWhat it means
Talk to a doctorbelow 0.8 Below 0,8 — context.
Good0.8 – 1.2 Within the reference range.
Talk to a doctor1.2 and aboveProlonged INR — clotting slowed; consult (medications/liver).
Source: ISTH (metoda)

Why it matters

ISTH: prolonged means slower clotting (liver/medications); monitors anticoagulation.

If it’s low

Low INR with warfarin means too little thinning (risk of a clot); otherwise low/normal is expected.

If it’s high

High INR means the blood clots more slowly — with warfarin, too high a dose (risk of bleeding), otherwise possibly liver disease or vitamin K deficiency.

What to do

If you take warfarin, a doctor manages the INR — do not change the dose yourself; watch for a steady intake of vitamin K (green vegetables) and interactions. Otherwise an abnormality is a liver hint.

Read together with

aPTT · Albumin · ALT

This content is for information only and is not a substitute for medical advice. Talk to your doctor about your results.

Your number, not the average

Upload your report: we rate your exact value for your age and sex, show the source, and tell you what to do next.

Start today

You already have the report. Get the answers.

Free. One minute. Your file stays in your browser.

Upload your report — free →