About the ABCD2 Score Calculator
The ABCD² score estimates the short-term risk of stroke after a transient ischaemic attack (TIA) — a brief episode of neurological symptoms caused by a temporary loss of blood flow. It adds points for Age, Blood pressure, Clinical features, Duration of symptoms and Diabetes, giving a total from 0 to 7.
It was derived and validated by Johnston and colleagues (Lancet 2007) in 4,809 patients diagnosed with TIA in emergency departments and clinics in the USA and UK. In that study a score of 0–3 carried a 1.0% stroke risk at 2 days, 4–5 a 4.1% risk and 6–7 an 8.1% risk. This calculator shows the score, the risk group and that published 2-day risk.
Current guidelines recommend that everyone with a suspected TIA is assessed urgently, ideally in a specialist service, whatever the score — a low ABCD² score does not exclude serious causes such as atrial fibrillation or carotid stenosis. Use the score as one input to clinical judgement, not as a triage decision on its own.
With the default inputs, the abcd² score is 4 / 7. Change any value above to recalculate instantly.
How to use the abcd2 score calculator
- 1Tick age 60 or older if it applies.
- 2Use the first blood pressure recorded after the event.
- 3Choose the most significant clinical feature: unilateral weakness outranks speech disturbance.
- 4Select how long symptoms lasted and whether the patient has diabetes.
- 5Read the score and risk group, and arrange urgent assessment whatever the result.
Formula and method
Points: age ≥ 60 years = 1; blood pressure ≥ 140/90 mmHg at first assessment = 1; clinical features — unilateral weakness = 2, speech impairment without weakness = 1; duration ≥ 60 minutes = 2, 10–59 minutes = 1; diabetes = 1. The maximum is 7.
In the validation cohorts, 34% of patients scored 0–3 (1.0% 2-day stroke risk), 45% scored 4–5 (4.1%) and 21% scored 6–7 (8.1%). The c statistics ranged from 0.62 to 0.83, meaning the score separates risk only moderately well — which is why later guidelines moved away from using it alone to decide who is seen urgently.
- A
- Age 60 or older
- B
- Blood pressure ≥ 140/90 mmHg
- C
- Clinical features (weakness or speech)
- D
- Duration of symptoms; Diabetes
Worked examples
68-year-old with 20 minutes of slurred speech
Age (1) + BP 150/90 (1) + speech disturbance without weakness (1) + duration 10–59 minutes (1) = 4, the moderate-risk group with a published 2-day stroke risk of 4.1%.
Diabetic with an hour of arm weakness
Age (1) + BP (1) + unilateral weakness (2) + duration ≥ 60 min (2) + diabetes (1) = 7, the maximum score and the 8.1% high-risk group.
Younger patient with brief visual symptoms
No points apply, so the score is 0. The low-risk group had a 1.0% 2-day stroke risk, but the patient still needs prompt assessment.
Frequently asked questions
What is a high ABCD2 score?+
A score of 6 or 7 is high risk, with an 8.1% stroke risk at 2 days in the original study. Scores of 4–5 are moderate risk (4.1%) and 0–3 are low risk (1.0%).
Is the ABCD2 score still used?+
It is still widely taught and recorded, but some guidelines — notably the UK NICE stroke guideline — now advise against using risk scores such as ABCD2 to decide urgency, because they miss important causes and every suspected TIA warrants rapid assessment.
What does each letter in ABCD2 stand for?+
Age, Blood pressure, Clinical features, Duration of symptoms and Diabetes. The squared "D" reflects the two D items: duration and diabetes.
Which clinical feature should I choose if there was weakness and speech trouble?+
Choose unilateral weakness (2 points). The speech item (1 point) only applies when speech was affected without any weakness, so the two are not added together.
What is a TIA?+
A transient ischaemic attack is a temporary episode of stroke-like symptoms — such as face or arm weakness, speech difficulty or vision loss — caused by brief interruption of blood supply, without lasting brain injury on imaging.
For healthcare professionals and education only. This calculator implements a published formula or score but is not a diagnosis and does not replace clinical judgment. Verify inputs and results against the original source before using them in patient care.