What is the CHA₂DS₂-VASc Bleeding Risk assessment?

This tool evaluates bleeding risk in patients with atrial fibrillation on anticoagulation, helping clinicians balance stroke prevention benefits of anticoagulation against the risk of major bleeding using patient-specific risk factors.

How does bleeding risk affect anticoagulation decisions?

High bleeding risk does not necessarily contraindicate anticoagulation, as the stroke risk from untreated atrial fibrillation often exceeds the bleeding risk. Instead, high-risk patients should receive modifiable risk factor optimization (blood pressure control, avoiding NSAIDs/alcohol), careful INR monitoring, and potentially DOACs over warfarin.

What are modifiable bleeding risk factors?

Modifiable bleeding risk factors include uncontrolled hypertension, labile INR (if on warfarin), concomitant use of antiplatelet agents or NSAIDs, and excessive alcohol consumption. Addressing these factors can significantly reduce bleeding risk while maintaining anticoagulation benefits.

Back to all tools

Home / HAS-BLED Score

HAS-BLED Bleeding Risk Score

Estimate annual major bleeding risk in patients with atrial fibrillation on anticoagulation. A high score does not contraindicate anticoagulation — it flags modifiable risk factors.

Inputs

Hypertension (uncontrolled SBP > 160 mmHg)

Abnormal renal function (dialysis, transplant, Cr > 2.26 mg/dL)

Abnormal liver function (cirrhosis, bilirubin > 2× ULN, AST/ALT > 3× ULN)

Stroke (prior history)

Bleeding (prior major bleeding or predisposition)

Labile INR (unstable/high INRs, TTR < 60%)

Elderly (age > 65)

Drugs (antiplatelets, NSAIDs)

Drinking (≥ 8 drinks/week)

HAS-BLED Score (0–9)

Low bleeding risk

Estimated annual major bleed risk—

Interpretation—

Disclaimer: For educational purposes only. A high HAS-BLED score does not contraindicate anticoagulation. It identifies patients who need closer follow-up and modification of reversible risk factors.

Scoring (HAS-BLED)

Hypertension (uncontrolled): +1
Abnormal renal function: +1
Abnormal liver function: +1
Stroke history: +1
Bleeding history/predisposition: +1
Labile INR (TTR < 60%): +1
Elderly (> 65): +1
Drugs (antiplatelets/NSAIDs): +1
Drinking (alcohol excess): +1

Risk stratification

0: ~1.13% annual major bleeding
1: ~1.02%
2: ~1.88%
3: ~3.74%
4: ~8.70%
≥ 5: ~12.5% (insufficient data at higher scores)
≥ 3: "High risk" — warrants caution and addressing modifiable risk factors

Clinical pearls

HAS-BLED ≥ 3 does not mean "don't anticoagulate" — it means identify and address modifiable factors.
Modifiable factors: uncontrolled BP, labile INR, concomitant antiplatelets/NSAIDs, alcohol excess.
"Labile INR" is less relevant for DOACs; some clinicians assign 0 for this criterion if on DOAC.
Use alongside CHA₂DS₂-VASc for balanced stroke vs. bleeding risk assessment.

References

Pisters R, et al. A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation. Chest. 2010;138(5):1093–1100.
ESC Guidelines for Atrial Fibrillation (2020).

Related tools

About This Tool

What Is the HAS-BLED Score?

HAS-BLED is a clinical prediction score that estimates the 1-year risk of major bleeding in patients with atrial fibrillation (AF) who are on or being considered for anticoagulation therapy. Published by Pisters et al. in 2010, it uses nine clinical variables forming the mnemonic HAS-BLED: Hypertension (uncontrolled), Abnormal renal/liver function, Stroke, Bleeding history, Labile INR, Elderly (>65), and Drugs/alcohol. Each item scores 1 point for a maximum of 9.

When to Use HAS-BLED

Calculate HAS-BLED alongside CHA₂DS₂-VASc in every AF patient being assessed for anticoagulation. It helps frame the risk-benefit conversation: the stroke risk (CHA₂DS₂-VASc) versus the bleeding risk (HAS-BLED). A HAS-BLED score ≥3 indicates "high bleeding risk" but does NOT contraindicate anticoagulation — rather, it identifies patients who need closer monitoring and active management of modifiable risk factors.

Interpreting HAS-BLED Results

Scores of 0–1 indicate low bleeding risk (~1% annual major bleeding). Score 2 is moderate risk (~1.9%). Scores ≥3 represent high bleeding risk (~3.7–12.5%). The clinical action for high scores is not to withhold anticoagulation but to address modifiable factors: control blood pressure, minimize concomitant antiplatelet/NSAID use, reduce alcohol intake, and improve INR control (or switch to DOAC).

🔑 Clinical Pearls

A high HAS-BLED score does NOT mean "don't anticoagulate." In almost all cases, the stroke risk from AF exceeds the bleeding risk. Use HAS-BLED to identify and fix modifiable risk factors.
The "Labile INR" criterion (TTR <60%) is less relevant for patients on DOACs. Some clinicians assign 0 for this criterion in DOAC-treated patients.
Many of the same risk factors that increase bleeding (age, hypertension, prior stroke) also increase stroke risk — the same patient often has high CHA₂DS₂-VASc AND high HAS-BLED.
2020 ESC guidelines recommend formal bleeding risk assessment using HAS-BLED at every clinical encounter, not just at initial anticoagulation decision.

Key References

Pisters R, et al. A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation. Chest. 2010;138(5):1093–1100.
Hindricks G, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation. Eur Heart J. 2021;42(5):373–498.
Lip GYH. Implications of the CHA₂DS₂-VASc and HAS-BLED Scores for Thromboprophylaxis in Atrial Fibrillation. Am J Med. 2011;124(2):111–114.

Formula last verified: February 2026