Cardiology
HAS-BLED Score
Major bleeding risk on anticoagulation in atrial fibrillation.
Education and reference only. Not a substitute for clinical judgement, local policy or product labelling. Always verify before clinical use. Values are calculated in your browser and never stored.
Background
HAS-BLED estimates the one-year risk of major bleeding in people with atrial fibrillation (AF) who are being considered for, or are taking, anticoagulation. It is used alongside a stroke-risk score (CHA₂DS₂-VASc) so that the decision balances the benefit of preventing stroke against the hazard of bleeding. One point is given for each of: Hypertension (uncontrolled, systolic >160 mmHg), Abnormal renal function, Abnormal liver function, prior Stroke, prior major Bleeding or predisposition, Labile INR (on warfarin), Elderly (age >65), and one point each — scored separately — for Drugs predisposing to bleeding (antiplatelets or NSAIDs) and for Alcohol excess. Abnormal renal and liver function are also scored separately, giving a maximum of 9.
Interpreting the result
Risk of major bleeding rises with the score. A score of 0–2 is regarded as lower risk, while a score of ≥3 indicates a high-risk patient who needs caution and more frequent review. Crucially, a high score is not a reason to withhold anticoagulation: its main value is to flag modifiable factors — uncontrolled blood pressure, labile INR, concurrent antiplatelets or NSAIDs and harmful alcohol intake — that can be corrected to lower the bleeding hazard.
Advice
A score ≥3 indicates higher bleeding risk and warrants caution and regular review, but is NOT a reason to withhold anticoagulation — address the modifiable factors.
Worked example
A 70-year-old on warfarin with poorly controlled hypertension and labile INRs scores: Elderly (1) + Hypertension (1) + Labile INR (1) = 3. This places the patient in the high-risk group, prompting tighter blood-pressure control and INR optimisation rather than stopping anticoagulation.
Pearls / pitfalls
- A high HAS-BLED score should trigger correction of modifiable risks and closer follow-up — it is not a reason to deny anticoagulation to a patient at genuine stroke risk.
- Several factors overlap with CHA₂DS₂-VASc (hypertension, prior stroke, older age), so the two scores are complementary, not interchangeable.
- The labile-INR point applies only to patients on warfarin; it does not apply to those on direct oral anticoagulants.
- Definitions matter: "abnormal renal/liver function" and "drugs/alcohol" have specific criteria — apply them consistently to avoid over- or under-scoring.
Evidence & validation
Derived and validated by Pisters and Lip et al. in a real-world AF cohort and endorsed by ESC and NICE guidance as a structured way to assess and modify bleeding risk in AF.
Frequently asked questions
Does a high HAS-BLED score mean anticoagulation should be stopped?
No. A score of ≥3 flags higher bleeding risk and the need for caution and review, but the main purpose is to identify and correct modifiable factors. Anticoagulation is generally still offered when stroke risk warrants it.
How does HAS-BLED relate to CHA₂DS₂-VASc?
CHA₂DS₂-VASc estimates stroke risk and HAS-BLED estimates bleeding risk; they are used together. The decision weighs the benefit of stroke prevention against the hazard of bleeding.
What counts as a high score?
A score of 0–2 is considered lower risk and ≥3 is high risk. A high score warrants caution, correction of modifiable factors and regular review.
Does the labile-INR point apply to people on DOACs?
No. The labile-INR criterion only applies to patients taking warfarin, where time in therapeutic range can be measured. It is not scored for direct oral anticoagulants.
Which factors are modifiable?
Uncontrolled hypertension, labile INR, concurrent antiplatelet or NSAID use, and harmful alcohol intake are all potentially correctable. Addressing these can meaningfully lower bleeding risk.
References
- 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. Chest. 2010;138(5):1093–1100.
- Hindricks G, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation. Eur Heart J. 2021.
- NICE NG196: Atrial fibrillation: diagnosis and management. 2021.
About the creator
Pisters R, Lip GYH et al.
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