Scores & indices
HAS-BLED calculator
Nine factors that tell you what to fix — not whether to stop the anticoagulant.
How to read the result
HAS-BLED falls into these published bands.
A 72-year-old with a systolic blood pressure of 168 mmHg who takes a daily NSAID for osteoarthritis, reviewed before anticoagulation for AF.
HAS-BLED 3 — high bleeding risk (~3.7 major bleeds per 100 patient-years)
Review rather than withhold: control the blood pressure, replace the NSAID, and schedule closer follow-up — two of the three points are fixable.
Who this is for
For clinicians starting or reviewing oral anticoagulation, usually straight after CHA₂DS₂-VASc. HAS-BLED counts uncontrolled hypertension, renal and liver dysfunction, prior stroke, bleeding history, labile INR, age over 65, antiplatelets or NSAIDs, and alcohol — and its job is to surface the modifiable ones and set the review interval, not to veto treatment.
How it works
What it calculates
Major-bleeding risk on oral anticoagulation from nine factors — hypertension, renal and liver function, stroke, bleeding history, labile INR, age over 65, antiplatelets/NSAIDs, and alcohol.
How to use it
A score of 3 or more flags high bleeding risk. Its purpose is to surface the modifiable factors — control the blood pressure, stop the NSAID, stabilise the INR — and to schedule closer review, not to veto anticoagulation.
The pairing
Read it alongside CHA₂DS₂-VASc: in most patients with a clear stroke-prevention indication, the ischaemic risk of withholding exceeds the bleeding risk of treating. Reference: Pisters et al., Chest 2010.
Built on published evidence
- Pisters et al., Chest 2010
Codification last reviewed 2026-08-28, and checked against published reference values in automated tests on every release — see the full evidence ledger.
Questions clinicians ask
Should a HAS-BLED of 3 or more stop anticoagulation?
Rarely. A score of 3 or more flags high bleeding risk, and the response is to correct the modifiable factors — blood pressure, INR stability, antiplatelets and NSAIDs, alcohol — and review more often. In most patients with a clear indication, the ischaemic risk of withholding exceeds the bleeding risk of treating.
What counts as hypertension in HAS-BLED?
Uncontrolled hypertension — a systolic blood pressure above 160 mmHg. A treated, controlled blood pressure does not score the point, which is exactly what makes it a modifiable factor worth chasing.
What does labile INR mean?
Time in therapeutic range below 60% on warfarin — unstable or frequently out-of-range INRs. It is a warfarin-specific criterion, and one of the factors an anticoagulation review can actually improve.
Where do the bleed rates come from?
Major-bleed rates per 100 patient-years from the Euro Heart Survey cohort (Pisters et al., Chest 2010). Scores of 6 and above had too few patients for a reliable estimate, so the tool does not quote a rate there.
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