An INR of 0.8 on warfarin
| Where it fallsthe target ranges used in warfarin management | Below the usual warfarin target |
|---|---|
| INRfor someone taking warfarin | 0.8 |
| Usual reference range | 2.0 – 3.0 for most indications |
| Below the usual warfarin targetthis reading | under 2 |
| Within the usual warfarin target | 2 – 2.9 |
| Above target | 3 – 4.4 |
| Well above target | 4.5 and above |
Notes
- One reading is not a diagnosis. INR moves with warfarin dose, vitamin K in the diet, alcohol, illness, and a long list of interacting medicines and supplements. A clinician reads it against your history and usually against a repeat, not on its own.
- Reference ranges differ between laboratories. The bands above follow the target ranges used in warfarin management. Your own report prints the range its analyser was calibrated against, and that printed range is the one to compare against — a difference of a few units between labs is normal and does not mean either is wrong.
- The INR only has a target if you are taking warfarin. Off warfarin it is a clotting measurement with a narrow normal range near 1.0, and a raised value points at liver disease, vitamin K deficiency or a clotting disorder. The 2.0–3.0 figure people quote is a treatment target, not a normal range, and applying it to someone not on warfarin inverts the meaning of the result.
- The target is not 2.0–3.0 for everyone on warfarin. A mechanical mitral valve is usually managed at 2.5–3.5, and some indications sit differently again. The range printed in the person's own anticoagulation record is the one that applies.
- Vitamin K in food is what moves it week to week. Green leafy vegetables, broccoli and some oils are the usual culprits — but the advice is a steady intake rather than avoidance, because swinging from none to plenty is what destabilises the INR. Alcohol, antibiotics, amiodarone, NSAIDs and St John's wort all shift it too.
What inr of 0.8 means
A reading of **0.8 **for someone taking warfarin falls in Below the usual warfarin target by the target ranges used in warfarin management.
The usual reference range is **2.0 – 3.0 for most indications **.
Reading it next to the rest of the picture
A single figure is a snapshot. What somebody experienced does with it is set by what sits around it — the other figures on the same report, the history behind them, and what the previous result was. Two people can hand over the same number and leave with different advice, and neither has been given the wrong answer.
That is also why the bands on this page are drawn from a named source rather than a rounded rule of thumb. A threshold is a decision point somebody argued for in print, not a law of nature, and knowing which document a line comes from is what lets you tell a meaningful result from a borderline one.
Nearby sizes
Read more
- CBC Normal Ranges — What Each Line on the Result MeansA value marked high or low on a CBC is common and is often not significant on its own. The pattern across lines is what a clinician reads.
- eGFR Normal Range: Above 90, and the Stages Below IteGFR is an estimate built from creatinine, age and sex — and the estimate is better than the raw creatinine it comes from, for a reason worth understanding.
- TSH Normal Range: 0.4–4.0 mIU/L, and the Number Moves BackwardsTSH runs opposite to the gland it measures. High TSH means the thyroid is underactive, and that inversion catches almost everyone reading their own result.
- Cholesterol Numbers: What Total, LDL, HDL and Triglycerides MeanA lipid panel reports four numbers and the one printed largest — total cholesterol — is the least useful of them.