HAS-BLED Score Calculator

HAS-BLED Calculator

Check all that apply. A and D each have two independent sub-components (max A=2, max D=2).

H — Uncontrolled hypertension (SBP >160 mmHg) +1

A — Abnormal Renal / Liver Function (each = 1 pt, max 2)

A (Renal) — Dialysis, renal transplant, or creatinine >200 µmol/L +1

A (Liver) — Cirrhosis, bilirubin >2× ULN, or transaminases >3× ULN +1

S — Prior stroke history +1

B — Prior major bleeding or bleeding predisposition (anaemia, thrombocytopenia) +1

L — Labile INR (TTR <60% if on warfarin) +1

E — Elderly (age >65 years) +1

D — Drugs / Alcohol (each = 1 pt, max 2)

D (Drugs) — Antiplatelet agents or NSAIDs +1

D (Alcohol) — Alcohol ≥8 drinks/week +1

Low Bleeding Risk

1.13

Bleeds/100 pt-yrs

Monitor

Action

Scoring Components

H	Uncontrolled Hypertension — SBP consistently >160 mmHg — 1 point
A (Renal)	Abnormal renal function: dialysis, transplant, or creatinine >200 µmol/L — 1 point
A (Liver)	Abnormal liver function: cirrhosis, bilirubin >2× ULN, or transaminases >3× ULN — 1 point
S	Prior stroke history — 1 point
B	Prior major bleeding or bleeding predisposition (anaemia, thrombocytopenia) — 1 point
L	Labile INR — TTR <60% if on warfarin — 1 point
E	Elderly age >65 years — 1 point
D (Drugs)	Concomitant antiplatelet agents or NSAIDs — 1 point
D (Alcohol)	Alcohol excess (≥8 drinks/week) — 1 point

Maximum score = 9. Note: A and D are each dual components — renal and liver dysfunction count separately, as do drugs and alcohol.

Bleeding Risk by Score

Score	Bleeds / 100 pt-yrs	Risk Category	Clinical Action
0	1.13	Low	Anticoagulate; routine monitoring
1	1.02	Low	Anticoagulate; routine monitoring
2	1.88	Low	Anticoagulate; routine monitoring
3	3.74	High	Anticoagulate WITH caution; address modifiable risk factors
4	8.70	High	Anticoagulate; urgently address all modifiable factors
≥5	>12	Very High	Anticoagulate only after addressing all modifiable factors; specialist review

Data from Pisters R et al. Chest 2010 (Euro Heart Survey cohort). pt-yrs = patient-years.

Critical Clinical Point: Do NOT Withhold Anticoagulation

Key principle: A high HAS-BLED score should trigger correction of modifiable bleeding risk factors — it should NEVER be used as a reason to withhold anticoagulation in a patient with high stroke risk (CHA₂DS₂-VASc ≥2). The net clinical benefit of anticoagulation almost always outweighs bleeding risk when stroke risk is high.

Modifiable HAS-BLED risk factors that can and should be actively corrected:

H — Uncontrolled hypertension: Optimise antihypertensive therapy to achieve SBP <140 mmHg.
A (Renal): Address reversible causes; adjust NOAC dose for eGFR (especially dabigatran — avoid if CrCl <30).
A (Liver): Treat underlying liver disease; avoid warfarin if advanced liver disease (unpredictable INR).
L — Labile INR: Switch from warfarin to a NOAC — this immediately removes this risk factor.
D — Drugs: Review and stop antiplatelet agents if not independently indicated (e.g., post-ACS, PCI). Review and stop NSAIDs; substitute with paracetamol or topical agents.
D — Alcohol: Alcohol cessation counselling; brief intervention; referral to addiction services.

Non-modifiable factors (S = prior stroke, B = prior bleeding, E = elderly) cannot be changed — they identify patients who need more vigilant monitoring rather than treatment cessation.

HAS-BLED vs. CHA₂DS₂-VASc: How to Use Together

Both scores should be calculated in every AF patient before initiating anticoagulation:

CHA₂DS₂-VASc ≥2 (men) or ≥3 (women): OAC indicated. Calculate HAS-BLED to identify what to fix.
If HAS-BLED ≥3: Do not withhold OAC. Address every modifiable risk factor. Consider NOAC over warfarin (removes the labile INR risk factor).
Reassess both scores periodically (at least annually or after any major change in clinical status) — risk factors evolve over time.
HAS-BLED was derived in warfarin-treated patients. Its performance with NOACs is slightly different but it remains clinically useful as a checklist of modifiable bleeding risk factors.

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, Potpara T, Dagres N, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation. Eur Heart J. 2021;42(5):373–498.
Lip GYH. Implications of the CHA₂DS₂-VASc and HAS-BLED Scores for Thromboprophylaxis in Atrial Fibrillation. Am J Med. 2011;124(2):111–114.

HAS-BLED Score

Scoring Components

Bleeding Risk by Score

Critical Clinical Point: Do NOT Withhold Anticoagulation

HAS-BLED vs. CHA₂DS₂-VASc: How to Use Together

References

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