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.

What is the HAS-BLED Bleeding Risk Score?

Score hypertension, abnormal renal or liver function, stroke history, prior bleeding, labile INR, age 65 or over, and drugs or alcohol use to yield the HAS-BLED major bleeding risk, helping clinicians balance anticoagulation against haemorrhage risk. It runs free in your browser on Gera Tools, with nothing uploaded.

HAS-BLED Bleeding Risk Score

Name: HAS-BLED Bleeding Risk Score
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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.

HAS-BLED is explicitly recommended by ESC atrial fibrillation guidelines not as a reason to withhold anticoagulation but as a structured prompt to identify factors that clinicians can actually fix — blood pressure, INR control, unnecessary NSAIDs — before starting or continuing therapy.

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.

Interpreting the result

Score	Interpretation	Typical clinical action
0–2	Low to moderate bleeding risk	Anticoagulation generally appropriate; review modifiable factors
≥3	High bleeding risk	Correct modifiable factors; do not withhold anticoagulation without strong reason

A high HAS-BLED score alongside a high CHA₂DS₂-VASc score means the patient has both high stroke risk and high bleeding risk. In this situation, anticoagulation is usually still recommended because the risk of a disabling stroke typically outweighs the bleeding risk — but the modifiable factors become urgent to address.

Modifiable versus non-modifiable factors

Modifiable factors (treat these):

Uncontrolled hypertension — treat with antihypertensives
Labile INR — switch to a DOAC, which avoids INR monitoring entirely
Concomitant antiplatelet drugs or NSAIDs — review necessity; many can be stopped
Alcohol excess — address with appropriate support

Non-modifiable factors (acknowledge these, increase monitoring):

Stroke history, prior major bleeding, age over 65, chronic renal or liver disease

The distinction matters clinically: a score of 4 made up of modifiable factors calls for action, while the same score from non-modifiable factors calls for careful monitoring and shared decision-making with the patient.

Worked 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, switch to a DOAC to eliminate labile INR, and stop the NSAID. After those changes the score drops to 1, and the stroke-prevention benefit of anticoagulation can be delivered with much lower haemorrhagic risk. Always read HAS-BLED alongside CHA₂DS₂-VASc, and remember the labile-INR item does not apply to patients already on direct oral anticoagulants.

This tool is for clinical reference only. All patient management decisions must be made by a qualified healthcare professional with access to the complete clinical picture.