What is the HAS-BLED score?

HAS-BLED is a validated clinical score that estimates the one-year risk of major bleeding in patients with atrial fibrillation who are candidates for, or already taking, oral anticoagulation. It helps clinicians identify and correct modifiable bleeding risk factors.

What HAS-BLED score is considered high risk?

A score of 3 or more indicates high bleeding risk and warrants caution, closer review, and correction of modifiable factors. It does not by itself contraindicate anticoagulation, because the stroke-prevention benefit often still outweighs the bleeding risk.

Does a high HAS-BLED score mean I should stop anticoagulation?

No. A high score should prompt you to address reversible factors such as uncontrolled hypertension, labile INR, and unnecessary antiplatelets or alcohol, and to arrange closer follow-up. It is not intended to be used on its own to withhold anticoagulation.

How does HAS-BLED relate to CHA₂DS₂-VASc?

CHA₂DS₂-VASc estimates stroke risk while HAS-BLED estimates bleeding risk. They are used together: in most patients with a treatment-level stroke risk, the benefit of anticoagulation outweighs bleeding risk, and HAS-BLED guides risk-factor optimisation rather than a yes or no decision.

What counts as labile INR?

Labile INR refers to unstable or high INRs on warfarin, conventionally a time in therapeutic range below 60 percent. It does not apply to patients on direct oral anticoagulants, for whom this criterion is not scored.

HAS-BLED Bleeding Risk Score

What the HAS-BLED score does

The HAS-BLED score estimates the one-year risk of major bleeding in patients with atrial fibrillation who are being considered for, or are already taking, oral anticoagulation. Its main clinical value is not to deny treatment but to flag and correct modifiable bleeding risks, so that the proven stroke-prevention benefit of anticoagulation can be delivered as safely as possible.

How it works

Each letter of the acronym scores points:

H — Hypertension (uncontrolled, systolic >160 mmHg): +1
A — Abnormal renal function (dialysis, transplant, or creatinine >200 µmol/L): +1, and Abnormal liver function (cirrhosis, or bilirubin >2× normal with AST/ALT/ALP >3× normal): +1
S — Stroke history: +1
B — Bleeding history or predisposition (prior major bleed or anaemia): +1
L — Labile INR (time in therapeutic range <60%, warfarin only): +1
E — Elderly, age >65: +1
D — Drugs (antiplatelet agents or NSAIDs): +1, and Alcohol excess (≥8 units/week): +1

Note that the “A” (renal and liver) and “D” (drugs and alcohol) each split into two separately scored items, giving a maximum of 9. A total of ≥3 indicates high bleeding risk.

Tips and example

A 70-year-old on warfarin with uncontrolled hypertension (+1), labile INR (+1), age >65 (+1), and regular NSAID use (+1) scores 4 — high bleeding risk. The right response is to control the blood pressure, improve INR stability, and stop the NSAID, not to withhold anticoagulation outright. Always read HAS-BLED alongside CHA₂DS₂-VASc, and remember the labile-INR item does not apply to direct oral anticoagulants.