UKMedCalc

For healthcare professionals. Educational tool only — not a medical device. Verify all results against the current BNF, NICE guidance and local policy, and apply clinical judgement.

Risk scoresCardiology

HAS-BLED — bleeding risk on anticoagulation

Estimates major bleeding risk in patients with atrial fibrillation considered for anticoagulation, highlighting modifiable risk factors.

HAS-BLED score

0

Lower bleeding risk

Estimated major bleeding rate
1.13 per 100 patient-yearsCohort estimate (Pisters 2010), warfarin-era data

Caveats & limitations

  • Derived largely from warfarin-era cohorts; absolute bleeding rates differ with DOACs.
  • Use to identify and correct modifiable risk factors, not to deny anticoagulation — stroke risk usually outweighs bleeding risk.
  • Labile INR applies only to warfarin patients; score 0 for that item in DOAC patients.
  • Reassess over time as factors change.

Evidence & UK guidance

Primary evidence

  • Pisters R, Lane DA, Nieuwlaat R, et al. A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation: the Euro Heart Survey. Chest. 2010;138(5):1093–1100.

    PubMedDOI

UK practice

NICE NG196 (2021 update) recommends the ORBIT score for assessing bleeding risk in AF, noting it may predict bleeding more accurately; HAS-BLED remains widely used and referenced in ESC guidance. In both approaches, a high score flags modifiable factors and the need for review — it is not, by itself, a reason to withhold anticoagulation.

Official resources

Formula and citations last verified: 2026-08-03

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NEWS2

The Royal College of Physicians' aggregate score for detecting deterioration in acutely ill adults — the NHS standard.