HAS-BLED Score Calculator — Bleeding Risk in AFib
Estimate the 1-year major bleeding risk for patients with atrial fibrillation on oral anticoagulation. The HAS-BLED score sums seven modifiable and non-modifiable risk factors — a score ≥ 3 signals high risk and prompts review of correctable factors.
H — Hypertension (uncontrolled SBP > 160 mmHg)
A — Abnormal renal or liver function
S — Stroke history
B — Bleeding history or predisposition
L — Labile INR (if on warfarin)
E — Elderly (age > 65 years)
D — Drugs or alcohol use
Range 0–9 — H + A + S + B + L + E + D
- 1
H + A + B + L
0 + 0 + 0 + 0 = 0Hypertension, abnormal renal/liver function, bleeding history and labile INR. - 2
S + E + D
0 + 0 + 0 = 0Stroke history, elderly (> 65) and drugs/alcohol. - 3
HAS-BLED total
0 + 0 = 0
How does this calculator work?
The HAS-BLED score (0–9) estimates 1-year major bleeding risk in anticoagulated AFib patients. Score 0–1 = low risk; 2 = moderate; ≥ 3 = high (≈ 3.7–8.7%/yr in original data). A high score should trigger correction of modifiable risks (BP, INR, antiplatelets, alcohol), not anticoagulation withdrawal. L criterion does not apply to DOACs.
Formula
How this is calculated
HAS-BLED was developed and validated in the Euro Heart Survey (Pisters et al., Chest 2010) to predict 1-year major bleeding events in anticoagulated atrial fibrillation patients. The seven components are scored 0–1 each, except abnormal renal/liver function (A) and drugs/alcohol (D), which can each contribute 0, 1, or 2 points, giving a maximum of 9. Higher scores correspond to higher annualised bleeding rates: score 0 ≈ 1.1%, score 1 ≈ 1.0%, score 2 ≈ 1.9%, score 3 ≈ 3.7%, score 4 ≈ 8.7% per year in the original cohort.
Critically, HAS-BLED is intended to identify modifiable bleeding risks — uncontrolled hypertension, labile INR, concomitant antiplatelet use, excessive alcohol — so they can be addressed, not as a reason to withhold anticoagulation. European (ESC) and North American guidelines note that most patients with high bleeding risk also have high stroke risk, and correcting modifiable factors reduces bleeding while maintaining the net benefit of anticoagulation.
Limitations: HAS-BLED was validated primarily in warfarin-treated cohorts. Its performance in patients on direct oral anticoagulants (DOACs) is broadly similar but the labile-INR criterion (L) does not apply to DOACs. Several competing bleeding-risk scores exist (HEMORR₂HAGES, ATRIA, ORBIT); no single score is definitively superior. Always integrate this score with full clinical assessment.
Frequently asked questions
Generally no. Guidelines (ESC 2020, AHA/ACC) state that a HAS-BLED score ≥ 3 should prompt identification and correction of modifiable risk factors (blood pressure control, stopping unnecessary antiplatelets, reducing alcohol intake, achieving stable INR), not cessation of anticoagulation. Most high-bleeding-risk patients also have high stroke risk, and the net benefit of anticoagulation is maintained after addressing correctable factors.
HAS-BLED was originally validated with warfarin but is broadly used for DOACs as well. The "L" criterion (labile INR) is specific to warfarin and does not apply to DOACs — score that item 0 for DOAC patients. The other six components remain clinically relevant.
Abnormal liver function is usually defined as cirrhosis, bilirubin more than twice the upper limit of normal, or ALT/AST/ALP more than three times the upper limit of normal in the absence of another explanation. Abnormal renal function is defined as chronic dialysis, renal transplant, or serum creatinine above 200 µmol/L (≈ 2.3 mg/dL).
Also known as
TG we-Calculate Editorial Team. (2026). HAS-BLED Score Calculator — Bleeding Risk in AFib [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/has-bled-calculator
TG we-Calculate Editorial Team. "HAS-BLED Score Calculator — Bleeding Risk in AFib." TG we-Calculate. 2026. https://we-calculate.com/calculator/has-bled-calculator.
TG we-Calculate Editorial Team, "HAS-BLED Score Calculator — Bleeding Risk in AFib," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/has-bled-calculator
@misc{wecalculate_has_bled_calculator, title = {HAS-BLED Score Calculator — Bleeding Risk in AFib}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/has-bled-calculator}}, year = {2026}, note = {TG we-Calculate} }
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