HAS-BLED Score Calculator
Major bleeding risk on anticoagulation with the HAS-BLED score — hypertension, renal or liver disease, stroke, bleeding history, labile INR, elderly, drugs or alcohol — with annual bleeding rate.
How it works
H hypertension 1 + A abnormal renal 1 / liver 1 + S stroke 1 + B bleeding 1 + L labile INR 1 + E elderly 1 + D drugs 1 / alcohol 1 (max 9)
HAS-BLED estimates the one-year risk of major bleeding in patients with atrial fibrillation on anticoagulation. Its value is not to decide against anticoagulation — stroke risk almost always dominates — but to flag correctable contributors: uncontrolled blood pressure, unstable INR (a reason to switch to a DOAC), concurrent aspirin or NSAIDs, and heavy drinking. A score of 3 or more is “high risk” and calls for closer monitoring. Note that several items also appear in CHA₂DS₂-VASc (age, hypertension, stroke), so stroke and bleeding risk often rise together. Renal and liver items score one point each, as do drugs and alcohol, giving a maximum of nine.
Worked example
A 72-year-old on warfarin with labile INR who takes aspirin: elderly 1 + INR 1 + drugs 1 = 3 — high risk, about 3.7 bleeds per 100 patient-years; switching to a DOAC and stopping aspirin would bring it to 1.
Frequently asked questions
Should I stop anticoagulation if HAS-BLED is high?
Guidelines say no — use the score to fix modifiable factors and follow up more closely. Withholding anticoagulation is only for very high, unmodifiable bleeding risk after specialist review.
Does the INR item apply to DOAC patients?
No — score it 0 for patients not on a vitamin K antagonist.
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Clinical decision tool for education and for use by trained clinicians alongside judgement — not a diagnosis and not a substitute for medical assessment. Scores validated in specific populations may not apply to every patient.