Stroke severity. Free to use.
NIHSS (Lite) (NIH Stroke Scale — Simplified) is a validated clinical instrument used to assess stroke severity. The instrument contains 13 items.
Source / attribution: Brott T et al., Stroke 1989 (NINDS-developed; public domain)
The instrument's primary construct — stroke severity — is operationalized through a fixed set of items, each with a defined response format. This standardisation is what allows NIHSS (Lite) scores to be compared meaningfully across clinicians, sites, and studies.
Like all screening or assessment instruments, NIHSS (Lite) is a structured aid — not a diagnostic test in isolation. Results should be interpreted alongside history, examination, and clinical context. Where a score crosses an actionable threshold, the next step is typically a more detailed clinical evaluation rather than a definitive diagnosis.
Answer all 13 items below to see your NIHSS (Lite) score and interpretation.
Each item is scored on a 4-point scale (0–3). Your score updates live as you answer.
All scoring runs in your browser. No data is sent anywhere — close the tab and the answers are gone.
NIHSS (Lite) uses simple summation: each item's selected response is converted to a numeric value, and the values are added to produce a total score. Reverse-scored items are inverted before summation.
Scoring notes: Simplified for bedside use; the official NIHSS includes additional scoring rules and untestable codes. NIH certification recommended for research use. Educational use only.
The cutoffs below are drawn from the published validation literature. Always interpret in clinical context.
| Score range | Band | Interpretation |
|---|---|---|
| 0–0 | No stroke symptoms | No stroke. |
| 1–4 | Minor stroke | Minor. |
| 5–15 | Moderate stroke | Moderate. |
| 16–20 | Moderate–severe stroke | Moderate–severe. |
| 21–42 | Severe stroke | Severe. |
This is an illustrative walkthrough, not a real patient. Follow the same four steps with your own answers — or use the live calculator at the top of this page.
Read each question and choose the response that best fits. Each response has a number next to it — that number is the item's score. The example below uses illustrative answers.
| # | Item | Example response | Score |
|---|---|---|---|
| 1 | 1a. Level of consciousness | Drowsy | 1 |
| 2 | 1b. LOC questions (month, age) | One correct | 1 |
| 3 | 1c. LOC commands (close eyes, grip) | One correct | 1 |
| 4 | 2. Best gaze | Partial gaze palsy | 1 |
| 5 | 3. Visual fields | Partial hemianopia | 1 |
| 6 | 4. Facial palsy | Minor | 1 |
| 7 | 5. Motor arm (worst side) | Drift | 1 |
| 8 | 6. Motor leg (worst side) | No drift | 0 |
| 9 | 7. Limb ataxia | One limb | 1 |
| 10 | 8. Sensory | Normal | 0 |
| 11 | 9. Best language | Mild aphasia | 1 |
| 12 | 10. Dysarthria | Normal | 0 |
| 13 | 11. Extinction / inattention | One modality | 1 |
Add up all the item scores you noted in Step 1.
1 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + … (items 9–13 sum to 3) = 10
Find the row in the interpretation table whose range contains your total:
Total = 10 falls between 5 and 15 → Moderate stroke
Moderate stroke. Moderate.
A score is one input alongside history and examination. NIHSS (Lite) supports clinical judgment — it does not replace it.
If NIHSS (Lite) doesn't fit your context, related instruments in neurology include:
| Scale | Measures | Items | Time |
|---|---|---|---|
| Glasgow Coma Scale | Level of consciousness after head injury | 3 | — |
| MoCA | Cognitive screening | — | ≈ 10 minutes |
| mRS | Functional outcome after stroke | 1 | — |
| ABCD2 | 2-day stroke risk after TIA | 5 | — |
| APGAR Score | Rapid assessment of newborn at 1 and 5 min | 5 | — |
| ASA Physical Status | Pre-operative health status | 1 | — |
| CHA2DS2-VASc | Annual stroke risk in non-valvular atrial fibrillation | 8 | — |
| CURB-65 | 30-day mortality in community-acquired pneumonia | 5 | — |
NIHSS (Lite) (NIH Stroke Scale — Simplified) is a validated instrument that assesses stroke severity. It is designed for clinicians, medical students, evidence-synthesis researchers. The 13 items are summed to produce a total score.
NIHSS (Lite) contains 13 items. Item scores are summed to produce the total. Scores run from 0 to 42, grouped into 5 interpretation bands from ‘No stroke symptoms’ up to ‘Severe stroke’.
On the NIHSS (Lite) (total score 0–42), scores of 21–42 fall in the ‘Severe stroke’ band — interpreted as: Severe. The full ladder is: 0 — No stroke symptoms: No stroke.; 1–4 — Minor stroke: Minor.; 5–15 — Moderate stroke: Moderate.; 16–20 — Moderate–severe stroke: Moderate–severe.; 21–42 — Severe stroke: Severe. A higher score reflects a more severe presentation, and crossing a cutoff is a prompt to step up assessment or care — but these bands are screening thresholds, not diagnoses.
Scores of 0 fall in the ‘No stroke symptoms’ band: No stroke. A low score is reassuring but does not by itself rule out the underlying condition — if symptoms or clinical suspicion persist, reassess over time or use a complementary evaluation rather than relying on the number alone.
Yes — NIHSS (Lite) is in the public domain and free for clinical, educational, and research use without permission. You can use this calculator and the scale itself freely; if you publish results or reproduce the scale, cite the original source paper.
Brott T et al. Stroke. 1989;20(7):864-870. This is the original publication for the NIHSS (Lite) — the reference to cite when reporting results.
No. NIHSS (Lite) is a structured assessment aid, not a diagnostic test. Its proper role is clinical assessment of stroke severity — it standardizes assessment and flags who needs closer evaluation, but the result must be weighed alongside history, examination, and clinical context. When a score conflicts with your clinical impression, clinical judgment takes precedence; treatment decisions should never rest on a screening score alone.
NIHSS (Lite) is supported by the following peer-reviewed sources: