Why is this score used?
Atrial fibrillation (AF) lets blood pool and form small clots in the heart, which can travel to the brain and cause a stroke. Blood-thinning medicines (anticoagulants) reduce that risk, but also carry a small risk of bleeding.
The CHA₂DS₂-VASc score helps weigh up that balance, so the decision about whether a blood thinner is likely to help is based on your individual risk factors.
What goes into the score?
The letters stand for risk factors that each add points: Congestive heart failure, High blood pressure, Age 75 or older (2 points), Diabetes, prior Stroke or mini-stroke/TIA (2 points), Vascular disease (such as previous heart attack), Age 65–74, and female Sex category.
Adding these up gives a score, usually from 0 to 9. A higher score means a higher estimated yearly stroke risk.
What does my score mean?
In general, a score of 0 in a man (or 1 in a woman from sex alone) suggests a low risk where blood thinners are often not needed. A score of 2 or more usually prompts a conversation about anticoagulation.
The score is a guide, not a decision on its own. Your doctor will also consider your bleeding risk, other conditions, and your own preferences before recommending anything.
Common questions
Does a high score mean I will have a stroke?
No. It estimates risk across many people with similar factors — it cannot predict what will happen to any one person. A higher score means blood thinners are more likely to be worthwhile.
Why does being female add a point?
Female sex slightly increases stroke risk in AF, but mainly when other risk factors are also present. On its own it does not usually mean a blood thinner is needed.
Should I start a blood thinner because of my score?
That is a decision to make with your doctor. They will balance your stroke risk against your bleeding risk and discuss the options with you. Do not start or stop any medicine without medical advice.
Related tools
These calculators are designed for healthcare professionals.