HAS-BLED Score Calculator
Estimate the one-year risk of major bleeding for someone with atrial fibrillation being considered for anticoagulation, using the HAS-BLED score. Each of nine factors adds one point. A high score is not a reason to withhold anticoagulation on its own — it flags patients who need closer review and correction of reversible bleeding risks. Tick the factors that apply.
The HAS-BLED factors
Hypertension (1), Abnormal renal function (1), Abnormal liver function (1), Stroke (1), Bleeding history or predisposition (1), Labile INR (1), Elderly ≥65 (1), Drugs (1), Alcohol (1) — maximum 9. Source: Pisters R et al., “A novel user-friendly score (HAS-BLED)…”, Chest 2010;138(5):1093–1100.
Frequently asked questions
What does HAS-BLED stand for?
HAS-BLED is a mnemonic for its factors: Hypertension (uncontrolled, systolic >160 mmHg), Abnormal renal or liver function (one point each), Stroke history, Bleeding history or predisposition, Labile INR (time in therapeutic range under 60%), Elderly (age ≥65), and Drugs or alcohol (one point each — antiplatelets/NSAIDs, and ≥8 drinks a week). Each factor scores one point, for a maximum of 9. The score was derived by Pisters and colleagues in 2010 from the Euro Heart Survey cohort of patients with atrial fibrillation, and it is intended for people being considered for, or already taking, oral anticoagulation. Several of its items are modifiable, so the acronym doubles as a checklist of things to correct rather than a fixed label.
What is a high HAS-BLED score?
A score of 0 is low risk, 1–2 is intermediate, and 3 or more is high risk of major bleeding. In the original cohort the major-bleeding rate rose from about 1 per 100 patient-years at a score of 0–1 to roughly 4 at a score of 3 and 9–12 at scores of 4–5. The value of a high score lies less in the number itself than in the modifiable items behind it — a systolic pressure above 160 mmHg, poor INR control, and concurrent antiplatelets, NSAIDs or heavy alcohol use. A score of 3 or more therefore triggers earlier review and correction of those factors, not withdrawal of treatment.
Does a high score mean I should stop anticoagulation?
A high HAS-BLED score is not a reason to stop anticoagulation. Current guidelines are explicit that it should not by itself be used to withhold anticoagulation, because the stroke risk it prevents usually outweighs the bleeding risk. Instead, a high score identifies patients for closer follow-up and for correcting reversible factors — uncontrolled blood pressure, labile INR, and unnecessary antiplatelets, NSAIDs or heavy alcohol use.
How does HAS-BLED relate to CHA₂DS₂-VASc?
HAS-BLED and CHA₂DS₂-VASc answer different questions. CHA₂DS₂-VASc estimates stroke risk to decide whether anticoagulation is warranted; HAS-BLED estimates bleeding risk to guide how safely to deliver it. They are used together — a high stroke risk with a manageable, reviewed bleeding risk still generally favours anticoagulation.
What counts as “labile INR”?
The labile INR criterion applies to patients on a vitamin-K antagonist such as warfarin whose INR is unstable or often out of range — conventionally a time in the therapeutic range below 60%. It does not apply to patients on a direct oral anticoagulant (DOAC), who do not have routine INR monitoring; leave it unchecked for them. Time in therapeutic range is the share of treatment time spent within the target INR band — usually 2.0 to 3.0 in atrial fibrillation — so readings that swing above and below that band score the point. It is one of the modifiable items the score is designed to surface, since better INR control removes the point rather than merely recording it.
This is a reference tool, not a diagnosis or medical advice. Results depend on the laboratory, assay and clinical context, and reference intervals vary between labs and by age and sex — always read your result against the range printed on your own report and discuss it with a qualified healthcare professional.
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