ABCD2 Score Calculator
Stroke risk after transient ischemic attack from age, blood pressure, symptoms, duration, and diabetes.
What it does
A transient ischemic attack is a brief episode of neurological dysfunction caused by a temporary lack of blood flow. The symptoms resolve, but the risk of a stroke in the next few days is real. The ABCD2 score was designed to sort that early risk using information available in the emergency department.
The name comes from five items: age, blood pressure, clinical features, duration, and diabetes. Age 60 or older earns 1 point. A systolic pressure of 140 or more, or a diastolic pressure of 90 or more, earns 1. Unilateral weakness earns 2, speech disturbance without weakness earns 1, and other symptoms earn 0. Symptoms lasting 60 minutes or more earn 2, 10 to 59 minutes earn 1, and under 10 minutes earn 0. Diabetes earns 1.
The total places the patient in one of three bands. Low risk is 0 to 3, moderate is 4 to 5, and high is 6 to 7. In the validation cohort, the two-day stroke risk was about 1.0% in the low band, 4.1% in the moderate band, and 8.1% in the high band. The seven-day risks were about 1.2%, 5.9%, and 11.7%.
The score is a triage aid, not a substitute for a workup. Current guidance recommends urgent specialist assessment and brain and vascular imaging for anyone with a suspected TIA, because the score alone is not sensitive enough to identify every patient at high risk. Carotid disease, atrial fibrillation, and the pattern of symptoms can change the plan.
The tool applies the original point weights. It does not distinguish anterior from posterior circulation, does not include imaging findings, and does not account for dual antiplatelet decisions. Those calls belong to the treating clinician, ideally within hours of the event.
How to use
- Enter the patient's age in years.
- Enter systolic and diastolic blood pressure from the first assessment.
- Choose the clinical feature that best matches the event.
- Choose the duration of the episode.
- Mark whether the patient has diabetes.
- Read the total, risk band, and the published two-day and seven-day stroke risks.
Formula
- A
- Age 60 years or older, 1 point.
- B
- Blood pressure at or above 140/90 mm Hg, 1 point.
- C
- Clinical features: unilateral weakness 2 points, speech disturbance without weakness 1 point, other 0.
- D
- Duration: 60 minutes or more 2 points, 10 to 59 minutes 1 point, under 10 minutes 0.
- D2
- Diabetes, 1 point.
The weakness and speech items are alternatives, not additions. If both are present, score unilateral weakness at 2 points. The blood pressure item is met when either the systolic or the diastolic threshold is reached. The duration refers to the episode itself, not the time since it ended. Risk bands are low 0 to 3, moderate 4 to 5, and high 6 to 7.
Worked example
Example: age 62, blood pressure 150/92, speech disturbance, 20 minutes, no diabetes
Age 62, systolic 150 mm Hg, diastolic 92 mm Hg, speech disturbance without weakness, symptoms lasting 20 minutes, no diabetes.
- Age 62 is 60 or older, so age scores 1.
- Systolic 150 is at least 140 and diastolic 92 is at least 90, so blood pressure scores 1.
- Speech disturbance without weakness scores 1.
- A duration of 20 minutes falls in the 10 to 59 minute band, so duration scores 1.
- No diabetes means 0 points.
- The total is 1 + 1 + 1 + 1 + 0 = 4, which is the moderate band (4 to 5).
- The published risks for that band are about 4.1% at two days and 5.9% at seven days.
Reference table
| Item | Points | Band | Score | 2-day risk | 7-day risk |
|---|---|---|---|---|---|
| Age 60 or older | +1 | Low | 0 to 3 | 1.0% | 1.2% |
| BP 140/90 or higher | +1 | Moderate | 4 to 5 | 4.1% | 5.9% |
| Unilateral weakness | +2 | High | 6 to 7 | 8.1% | 11.7% |
| Speech disturbance alone | +1 | ||||
| Duration 60 minutes or more | +2 | ||||
| Duration 10 to 59 minutes | +1 | ||||
| Diabetes | +1 |
Limits
- Applies to transient ischemic attack, not to completed stroke or to symptoms that are still present.
- Does not include imaging, carotid stenosis, atrial fibrillation, or the vascular territory involved.
- The risk percentages come from cohort data and vary across populations and care settings.
- A low score does not remove the need for urgent assessment, since the score misses some high-risk patients.
Common mistakes
- Adding weakness and speech points together instead of choosing the higher one.
- Scoring the time since symptoms resolved rather than the duration of the episode.
- Using a blood pressure reading from after treatment instead of the first assessment.
- Applying the score to a patient with persistent symptoms, which is a stroke until proven otherwise.
- Using a low score to delay imaging or specialist review.
Try it yourself
Quick checks. Answers sit tucked under each question.
Age 55, blood pressure 130/80, other symptoms, under 10 minutes, no diabetes?
Score 0, low risk, with a two-day risk of 1.0% and a seven-day risk of 1.2%.
Age 70, blood pressure 160/95, unilateral weakness, 75 minutes, diabetes?
Score 7, high risk, with a two-day risk of 8.1% and a seven-day risk of 11.7%.
Age 60, blood pressure 140/90, speech disturbance, under 10 minutes, diabetes?
Score 4, moderate risk, with a two-day risk of 4.1% and a seven-day risk of 5.9%.
Questions
What does ABCD2 stand for?
Age, Blood pressure, Clinical features, Duration, and Diabetes. The 2 marks the second version of the score.
What is a high ABCD2 score?
A score of 6 or 7 is the high risk band, with a published two-day stroke risk near 8.1%.
Does a low score mean no urgent care?
No. Guidelines recommend urgent specialist assessment and imaging for suspected TIA regardless of the score.
How is duration measured?
It is the length of the episode itself. Under 10 minutes scores 0, 10 to 59 minutes scores 1, and 60 minutes or more scores 2.
What if both weakness and speech changes are present?
Score unilateral weakness at 2 points and do not add the speech point, because the items are alternatives.
Is ABCD2 used for minor stroke?
No. It was built for transient ischemic attack. Minor stroke needs its own assessment and imaging.
Sources
- Johnston et al., validation and refinement of early stroke risk scores after TIA, Lancet 2007
- BMJ Evidence-Based Medicine: ABCD2 score for TIA commentary