NIH Stroke Scale (NIHSS) — free guideline decision tool
Quantify acute stroke severity with the NIH Stroke Scale (NIHSS, 0–42).
Open guideline tool →Guideline-based
Implements the decision logic from published clinical guidelines.
Runs in your browser
No installation. Enter the patient's values and get a guideline recommendation instantly.
Data stays local
Nothing is uploaded. Results are for licensed clinicians only.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| 1a. Level of consciousness | Drowsy (1) |
|---|---|
| 1b. LOC questions (month, age) | One correct (1) |
| 1c. LOC commands (open eyes, grip) | One (1) |
| 2. Best gaze | Partial palsy (1) |
| 3. Visual fields | Partial hemianopia (1) |
| 4. Facial palsy | Minor (1) |
| 5a. Left arm motor | Some effort vs gravity (2) |
| 5b. Right arm motor | Some effort vs gravity (2) |
| 6a. Left leg motor | Some effort vs gravity (2) |
| 6b. Right leg motor | Some effort vs gravity (2) |
| 7. Limb ataxia | One limb (1) |
| 8. Sensory | Mild–moderate loss (1) |
| 9. Best language | Mild–moderate aphasia (1) |
| 10. Dysarthria | Mild–moderate (1) |
| 11. Extinction/inattention | One modality (1) |
→NIHSS19/42
- Severity：Moderate–severe stroke
- Note：Higher scores predict larger infarcts and worse outcome; used to guide reperfusion decisions and track change.
| 1a. Level of consciousness | Alert (0) |
|---|---|
| 1b. LOC questions (month, age) | Both correct (0) |
| 1c. LOC commands (open eyes, grip) | Both (0) |
| 2. Best gaze | Normal (0) |
| 3. Visual fields | No loss (0) |
| 4. Facial palsy | Normal (0) |
| 5a. Left arm motor | No drift (0) |
| 5b. Right arm motor | No drift (0) |
| 6a. Left leg motor | No drift (0) |
| 6b. Right leg motor | No drift (0) |
| 7. Limb ataxia | Absent (0) |
| 8. Sensory | Normal (0) |
| 9. Best language | Normal (0) |
| 10. Dysarthria | Normal (0) |
| 11. Extinction/inattention | Normal (0) |
→NIHSS0/42
- Severity：No stroke symptoms
- Note：Higher scores predict larger infarcts and worse outcome; used to guide reperfusion decisions and track change.
Common questions
What NIHSS cut-off triggers thrombolysis or thrombectomy?
Thresholds follow guidelines and the local stroke pathway; NIHSS alone does not decide. Combine imaging, time window, and contraindications. Computed locally in the browser; patient data are not uploaded. For licensed clinicians only; combine with history, exam, and local protocol — not a standalone decision.
Can NIHSS replace head imaging to exclude hemorrhage or LVO?
No. NIHSS does not replace imaging to exclude intracranial hemorrhage or large-vessel occlusion. Computed locally in the browser; patient data are not uploaded. For licensed clinicians only; combine with history, exam, and local protocol — not a standalone decision.
Can untrained staff score NIHSS independently?
No reliable independent scoring without standard NIHSS training. Computed locally in the browser; patient data are not uploaded. For licensed clinicians only; combine with history, exam, and local protocol — not a standalone decision.
Are patient data uploaded, and where is the score calculated?
Computed locally in the browser; patient data are not uploaded. For licensed clinicians only; combine with history, exam, and local protocol — not a standalone decision.
How is NIH Stroke Scale (NIHSS) calculated in practice? Can you show a worked example?
Inputs: 1a. Level of consciousness Drowsy (1), 1b. LOC questions (month, age) One correct (1), 1c. LOC commands (open eyes, grip) One (1), 2. Best gaze Partial palsy (1), 3. Visual fields Partial hemianopia (1), 4. Facial palsy Minor (1), 5a. Left arm motor Some effort vs gravity (2), 5b. Right arm motor Some effort vs gravity (2)… → Result: NIHSS 19 /42（Severity: Moderate–severe stroke, Note: Higher scores predict larger infarcts and worse outcome; used to guide reperfusion decisions and track change.） Inputs: 1a. Level of consciousness Alert (0), 1b. LOC questions (month, age) Both correct (0), 1c. LOC commands (open eyes, grip) Both (0), 2. Best gaze Normal (0), 3. Visual fields No loss (0), 4. Facial palsy Normal (0), 5a. Left arm motor No drift (0), 5b. Right arm motor No drift (0)… → Result: NIHSS 0 /42（Severity: No stroke symptoms, Note: Higher scores predict larger infarcts and worse outcome; used to guide reperfusion decisions and track change.）
Run NIH Stroke Scale (NIHSS) now
Quantify acute stroke severity with the NIH Stroke Scale (NIHSS, 0–42).
Open guideline tool →For licensed clinicians. Not a substitute for clinical judgement.
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