NIH Stroke Scale (NIHSS) Calculator

Score stroke severity using the NIH Stroke Scale (NIHSS) Calculator. Enter assessments for 11 neurological domains — including level of consciousness, gaze, visual fields, facial palsy, motor arm/leg, limb ataxia, sensory, language, dysarthria, and extinction — and get your total NIHSS score with corresponding stroke severity classification.

Disclaimer: This tool is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making any health-related decisions.

Level of alertness and responsiveness

Ask patient the current month and their age

Ask patient to blink eyes and squeeze/release non-paretic hand

Horizontal eye movements only

Test upper and lower quadrants by confrontation

Assess symmetry of grimace in response to pain if unresponsive

Arm extended 90° (seated) or 45° (supine); score drift/fall

Arm extended 90° (seated) or 45° (supine); score drift/fall

Leg held at 30° supine; score drift/fall

Leg held at 30° supine; score drift/fall

Finger-nose-finger and heel-shin tests; score only if out of proportion to weakness

Test with pinprick; score only stroke-related loss

Describe picture, name items, read sentences

Read or repeat words; do not tell patient why they are being tested

Use simultaneous bilateral stimulation for visual and tactile extinction

Results

Total NIHSS Score

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Stroke Severity

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Scored Items

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Frequently Asked Questions

What is the NIH Stroke Scale (NIHSS)?

The NIH Stroke Scale is a standardized neurological assessment tool used by clinicians to objectively quantify the impairment caused by a stroke. It evaluates 11 domains including consciousness, vision, motor function, sensation, language, and attention. Scores range from 0 (no deficit) to 42 (most severe).

How is the NIHSS score interpreted?

A score of 0 indicates no stroke symptoms. Scores 1–4 suggest a minor stroke, 5–15 a moderate stroke, 16–20 a moderate-to-severe stroke, and 21–42 a severe stroke. Higher scores are associated with worse outcomes and greater infarct volume.

Who should administer the NIHSS?

The NIHSS is designed to be administered by trained healthcare professionals, including physicians, nurses, and paramedics. While formal certification is recommended for research settings, clinicians can use it in routine practice after reviewing administration guidelines.

Can the NIHSS be used to determine eligibility for tPA (alteplase)?

Yes. The NIHSS is one of several criteria considered when evaluating eligibility for IV thrombolysis (tPA). Patients with rapidly improving deficits (very low NIHSS) or very severe strokes (very high NIHSS) may require special consideration. Always follow your institution's stroke protocol.

What does 'UN' (untestable) mean in the NIHSS?

'UN' is recorded for items that cannot be assessed due to physical barriers, such as amputation, joint fusion, or intubation. Untestable items do not contribute to the total score, and this calculator excludes those items from the sum accordingly.

How often should the NIHSS be repeated?

The NIHSS is typically assessed at initial presentation, at 24 hours, at 7–10 days or discharge, and at 3 months. Serial assessments help track neurological improvement or deterioration and inform decisions about escalation of care.

Is the NIHSS validated for posterior circulation strokes?

The NIHSS is known to underestimate deficits in posterior circulation strokes, as it does not specifically assess cerebellar function, diplopia, vertigo, or dysconjugate gaze in detail. Clinicians should interpret scores cautiously in patients with brainstem or cerebellar involvement.

What is the maximum possible NIHSS score?

The maximum NIHSS score is 42, though in practice scores above 30 are rarely seen. A score of 42 would indicate severe impairment across all assessed domains. Scores above 25 generally indicate a very severe stroke with poor prognosis for functional independence.