HAS-BLED Bleeding Risk Score
Hypertension, Abnormal renal/liver function, Stroke history, Bleeding history, Labile INR, Elderly (age >65), Drugs/alcohol
Estimate major bleeding risk in atrial fibrillation patients on anticoagulation. HAS-BLED score identifies modifiable bleeding risk factors per ESC 2020 guidelines.
What is the HAS-BLED?
HAS-BLED is the most widely validated bleeding risk score for patients with atrial fibrillation who are receiving or being considered for oral anticoagulation. It was developed to help clinicians identify and address modifiable bleeding risk factors rather than to withhold anticoagulation. A high HAS-BLED score should prompt correction of reversible risks (uncontrolled hypertension, labile INR, concurrent antiplatelet/NSAID use, alcohol excess) and more frequent clinical review — not automatic exclusion from anticoagulation. Used alongside CHA₂DS₂-VASc in the ESC AF management pathway.
When to use it
Assess in all AF patients being considered for or already receiving anticoagulation. Use in parallel with CHA₂DS₂-VASc to balance stroke prevention against bleeding risk. Most useful for flagging modifiable bleeding risks that can be corrected before or during anticoagulation.
Scoring Criteria
HAS-BLED — Variables & Points
Hypertension (uncontrolled, SBP >160 mmHg)
Abnormal renal function (dialysis, transplant, creatinine >200 µmol/L)
Abnormal liver function (cirrhosis, bilirubin >2×ULN, ALT/AST/ALP >3×ULN)
Stroke history
Bleeding history or predisposition (anaemia)
Labile INR (time in therapeutic range <60%)
Elderly (age >65 years)
Drugs (antiplatelets, NSAIDs) or alcohol (≥8 units/week)
Drugs = 1 point; alcohol = 1 point; both possible simultaneously
Score Interpretation
Low bleeding risk
Anticoagulation appropriate; standard follow-up
Moderate bleeding risk
Address modifiable factors; anticoagulation still appropriate
High bleeding risk
Correct modifiable risks; frequent clinical review; do not withhold anticoagulation based on score alone
Guideline Recommendation
ESC 2020 AF Guidelines: HAS-BLED should be used to identify and correct modifiable bleeding risk factors (Class IIa, Level B). A high score is not a contraindication to anticoagulation — net clinical benefit of anticoagulation typically outweighs bleeding risk in high CHA₂DS₂-VASc patients.
Clinical Pearls
A score ≥3 flags high bleeding risk but should NOT automatically lead to withholding anticoagulation — the stroke risk almost always outweighs bleeding risk.
Focus on correcting the modifiable items: control blood pressure, review concurrent drugs (stop NSAIDs/antiplatelets if possible), address alcohol use, and optimise INR control.
Patients on NOACs may have a lower actual bleeding risk than their HAS-BLED score suggests because NOACs avoid the labile INR criterion by definition.
Reassess at every clinical review — modifiable factors can be resolved, lowering the score.
Limitations
Maximum score is technically >9 with both drug and alcohol components — calibration above 3 is less reliable.
Does not distinguish between major and minor bleeding events.
Less validated for NOACs than for warfarin in original derivation cohorts.
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Frequently Asked Questions
What HAS-BLED score is considered high risk?
A score of ≥3 is classified as high bleeding risk by ESC guidelines. However, this should prompt correction of modifiable bleeding risk factors and more frequent monitoring — not automatic discontinuation or withholding of anticoagulation.
Can I use HAS-BLED to decide whether to start anticoagulation?
HAS-BLED is designed to identify modifiable bleeding risks, not to override the anticoagulation decision. Pair it with CHA₂DS₂-VASc — for most patients with score ≥2 on CHA₂DS₂-VASc, the net clinical benefit of anticoagulation outweighs the bleeding risk even with a high HAS-BLED score.
What counts as labile INR for HAS-BLED?
Time in therapeutic range (TTR) less than 60% on warfarin qualifies. If the patient is on a NOAC, this criterion does not apply — NOACs eliminate INR variability, which is one advantage they hold over warfarin in patients with labile INR.