Used for people with atrial fibrillation or atrial flutter to estimate stroke risk and help decide whether a blood thinner makes sense. Check every box that applies to you, or enter your age below.
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This estimate is for education only and doesn't replace your care team's judgment — the decision to start or avoid a blood thinner also weighs your individual bleeding risk (see the HAS-BLED score), your personal preferences, and factors this calculator doesn't capture. Talk to your doctor about what your result means for you.
What the Letters Stand For
| Letter | Factor | Points |
|---|---|---|
| C | Congestive heart failure / reduced pumping function | 1 |
| H | Hypertension | 1 |
| A₂ | Age 75 or older | 2 |
| D | Diabetes | 1 |
| S₂ | Prior stroke, TIA, or clot | 2 |
| V | Vascular disease | 1 |
| A | Age 65–74 | 1 |
| Sc | Sex category (female) | 1 |