Clinical tool
CHA₂DS₂-VASc
Stroke risk in atrial fibrillation.
CHA₂DS₂-VASc
0/ 9
Select age group and sex
The category depends on sex, because female sex adds a point but is a risk modifier rather than an independent risk factor.
Still to choose: Age, Sex.
This score supports risk stratification and should be interpreted alongside the overall clinical context and current treatment guidance.
Score support, not a decision
What this calculates
Stroke risk in non-valvular atrial fibrillation: heart failure, hypertension, age, diabetes, prior stroke, vascular disease and sex, from 0 to 9.
When to use it
When deciding whether oral anticoagulation should be offered to a patient with atrial fibrillation.
How to interpret it
Female sex adds one point but is a risk modifier, not an independent risk factor, so the thresholds differ by one point between men and women. Anticoagulation is generally recommended from 2 in men and 3 in women, and considered at 1 in men and 2 in women.
Important limitations
- It does not apply to moderate to severe mitral stenosis or a mechanical valve, which need anticoagulation regardless.
- Some current guidelines use CHA₂DS₂-VA, which omits sex. Follow the guidance your service uses.
- Bleeding risk is assessed separately, and a high bleeding score is a prompt to address modifiable factors.
For practising medics only. Clinical tools support judgement, they do not replace it. Always verify results against current guidelines and the patient in front of you.