Ask patient to show teeth or smile. (0=Normal, 1=Minor, 2=Partial, 3=Complete)
5a. Motor Arm — Left0–4
Extend arm 90° (sitting) or 45° (supine) for 10 seconds. (0=No drift, 4=No movement)
5b. Motor Arm — Right0–4
Extend arm 90° (sitting) or 45° (supine) for 10 seconds. (0=No drift, 4=No movement)
6a. Motor Leg — Left0–4
Extend leg 30° (supine) for 5 seconds. (0=No drift, 4=No movement)
6b. Motor Leg — Right0–4
Extend leg 30° (supine) for 5 seconds. (0=No drift, 4=No movement)
7. Limb Ataxia0–2
Finger-to-nose and heel-to-shin testing. (0=Absent, 1=Present in one limb, 2=Present in two limbs)
8. Sensory0–2
Sensation to pinprick. (0=Normal, 1=Mild-to-moderate loss, 2=Severe loss)
9. Best Language0–3
Describe a picture, name objects, read sentences. (0=Normal, 3=Mute/Global aphasia)
10. Dysarthria0–2
Read or repeat words. (0=Normal, 1=Mild-to-moderate, 2=Severe/Anarthria)
11. Extinction/Inattention0–2
Double simultaneous stimulation testing. (0=Normal, 1=Extinction in one modality, 2=Profound hemi-inattention)
Total NIHSS Score
0
Out of 42
Stroke Severity
Normal
Clinical interpretation
Items Scored
0/15
Categories completed
Neurological Deficit
No stroke symptoms
Patient assessment
📋 NIHSS Score Breakdown
NIHSS Score Interpretation
The NIH Stroke Scale (NIHSS) total score ranges from 0 to 42. Higher scores indicate greater neurological impairment and more severe stroke.
Total Score
Severity
Clinical Description
0
No Stroke Symptoms
No neurological deficits detected. Normal neurological examination.
1–4
Minor Stroke
Minor neurological impairment. Patients generally have good outcomes with appropriate treatment.
5–15
Moderate Stroke
Moderate neurological deficits. Significant impairment requiring acute intervention and rehabilitation.
16–20
Moderate-to-Severe Stroke
Moderately severe deficits. High likelihood of disability. Intensive care and monitoring recommended.
21–42
Severe Stroke
Severe neurological impairment. High risk of complications, poor functional outcomes, and mortality.
0
No Stroke
No symptoms detected
1–4
Minor
Mild impairment
5–15
Moderate
Significant deficits
16–20
Moderate-Severe
Major disability risk
21–42
Severe
Critical condition
Key Clinical Considerations
🔹 Baseline Assessment: The initial NIHSS score is a strong predictor of 3-month functional outcome. Each additional point on the baseline NIHSS decreases the probability of an excellent outcome by approximately 17%.
🔹 Serial Assessments: Changes in NIHSS score over time (e.g., at 24 hours, day 7, or at discharge) are used to monitor neurological recovery or deterioration. A decrease of 4 or more points is considered a clinically significant improvement.
🔹 Treatment Decisions: Patients with NIHSS scores ≥ 4 are generally considered candidates for acute stroke interventions such as intravenous thrombolysis (tPA) or mechanical thrombectomy, though individual clinical judgment and time constraints apply.
🔹 Prognostic Value: Baseline NIHSS score is one of the strongest predictors of stroke outcome. Scores > 20 are associated with high mortality, while scores < 10 are associated with favorable outcomes in most cases.
How to Use the NIH Stroke Scale
The National Institutes of Health Stroke Scale (NIHSS) is a systematic assessment tool that provides a quantitative measure of stroke-related neurological deficits. It is widely used in clinical settings, clinical trials, and emergency medicine.
Quick Guide to Scoring
1
Assess LOC (Items 1a–1c): Begin with level of consciousness — determine if the patient is alert, responsive to voice, responsive to pain, or unresponsive. Then test orientation with two standard questions and ability to follow two commands.
2
Evaluate Cranial Nerves (Items 2–4): Test horizontal gaze, visual fields by confrontation, and facial symmetry. These assess brainstem and cortical function.
3
Test Motor Function (Items 5–6): Assess arm and leg strength on both sides separately. Position arms at 90° (sitting) or 45° (supine) for 10 seconds; legs at 30° for 5 seconds. Score the drift based on observed movement.
4
Check Coordination & Sensation (Items 7–8): Limb ataxia is tested with finger-to-nose and heel-to-shin maneuvers. Sensory testing uses pinprick on arms, legs, trunk, and face.
5
Assess Language & Speech (Items 9–10): Evaluate language comprehension and expression by asking the patient to describe a scene, name objects, and read sentences. Dysarthria is tested by having the patient read or repeat words.
6
Evaluate Extinction (Item 11): Test for sensory neglect using double simultaneous stimulation (visual, tactile, auditory). Note if one side is extinguished.
Important Notes for Accurate Scoring
⏱️ Time Matters
Complete the NIHSS assessment within 10–15 minutes. Prolonged assessment may delay critical acute stroke treatments.
📝 Score What You See
Score based on actual patient performance, not what you think the patient should be capable of. Do not coach or prompt patients.
🔄 Consistency
Use the same version of the NIHSS for serial assessments to ensure comparability. The original 11-item (15-point) scale is the standard.
🏥 Clinical Context
The NIHSS score should be interpreted in the context of the patient's history, imaging findings, and overall clinical picture.
🧠
Complete NIHSS Assessment
All 15 NIH Stroke Scale categories included — from level of consciousness to extinction/inattention — for a comprehensive neurological evaluation.
📊
Instant Severity Classification
Automatically classifies stroke severity from no symptoms to severe stroke based on the total NIHSS score (0–42 scale).
📋
Score Breakdown
View a detailed breakdown of each category score with clinical interpretation, helping track specific neurological deficits.
🏥
Evidence-Based Tool
Based on the validated NIH Stroke Scale used in clinical trials, emergency departments, and stroke centers worldwide.
The National Institutes of Health Stroke Scale (NIHSS) is a standardized, 15-item neurological examination that provides a quantitative measure of stroke-related neurological deficits. Developed in the 1980s, it has become the gold standard for assessing stroke severity in clinical practice and research worldwide. The scale evaluates key domains including level of consciousness, vision, motor function, sensation, language, speech, and attention.
The NIHSS total score ranges from 0 to 42, with higher scores indicating more severe neurological impairment. Each of the 15 items scores specific neurological functions on a scale of 0 (normal) to 2, 3, or 4 (maximum deficit). The scale is designed to be administered in approximately 5–10 minutes by trained healthcare professionals, making it practical for use in emergency settings where rapid assessment is critical for treatment decisions.
Why the NIHSS Matters in Stroke Care
The NIHSS serves multiple critical functions in stroke care. First, it provides a common language for healthcare providers to communicate stroke severity — a patient with an NIHSS of 22 is universally understood to have a severe deficit regardless of the treating facility. Second, baseline NIHSS score is one of the strongest predictors of 3-month functional outcomes and helps guide treatment decisions, including eligibility for thrombolytic therapy and mechanical thrombectomy. Third, serial NIHSS assessments allow clinicians to track neurological improvement or deterioration over time, providing objective data on treatment response.
How to Use This Calculator
Using the NIH Stroke Scale Calculator is straightforward. For each of the 15 categories, select the score that best describes the patient's performance on that specific neurological test. The NIHSS is designed to be administered by trained healthcare professionals following standard instructions. Score each item based on what the patient actually does, not what you think they could do under different circumstances.
After completing all 15 items, click "Calculate NIHSS Score" to obtain the total score, severity classification, and a detailed breakdown of findings. This tool is intended for healthcare professionals familiar with the NIHSS administration guidelines. For accurate results, ensure you have completed NIHSS certification training, which is available through the American Stroke Association and other accredited organizations.
Key Domains Assessed
🧠 Consciousness & Cognition
Items 1a–1c assess level of consciousness, orientation to time and place, and ability to follow commands — fundamental indicators of neurological status.
👁️ Cranial Nerve Function
Items 2–4 evaluate horizontal gaze, visual fields, and facial motor function to identify brainstem and cortical involvement.
💪 Motor Strength
Items 5–6 assess arm and leg strength bilaterally, detecting hemiparesis and grading its severity from no drift to complete paralysis.
🗣️ Language & Speech
Items 9–10 evaluate expressive and receptive language function along with articulation, identifying aphasia and dysarthria.
Frequently Asked Questions
What is a normal NIHSS score?
A score of 0 on the NIH Stroke Scale indicates no stroke symptoms — the patient's neurological examination is normal. However, it's important to note that the NIHSS does not capture all possible neurological deficits. Some subtle findings (e.g., minor ataxia, mild sensory loss) may still be present despite a score of 0. The NIHSS is most valuable as a measure of stroke severity when the score is elevated.
What does an NIHSS score of 5–15 mean?
An NIHSS score of 5–15 indicates a moderate stroke. At this level, patients have significant neurological deficits that typically require hospitalization, acute stroke interventions, and rehabilitation. These patients often benefit from intravenous thrombolysis (tPA) if within the therapeutic window and may be candidates for mechanical thrombectomy depending on imaging findings. The prognosis is variable — many patients with moderate strokes can achieve good functional outcomes with timely, appropriate treatment.
What is the maximum NIHSS score?
The maximum total score on the NIH Stroke Scale is 42, representing the most severe neurological impairment. A score of 42 occurs when a patient scores the maximum deficit on every item — typically seen in patients with massive hemispheric strokes, brainstem strokes causing locked-in syndrome, or global cerebral injury. Scores above 20 are classified as severe and are associated with high mortality and poor functional outcomes. However, patients with very high NIHSS scores may still benefit from aggressive treatment in appropriate clinical contexts.
How long does it take to administer the NIHSS?
The NIH Stroke Scale is designed to be administered in approximately 5–10 minutes by a trained healthcare professional. Speed comes with practice — experienced clinicians can complete the assessment in under 5 minutes. The scale was deliberately designed to be brief enough for use in emergency settings where "time is brain," yet comprehensive enough to capture the major domains of neurological function affected by stroke. NIHSS certification, available through the American Stroke Association, typically takes 2–3 hours to complete and is valid for 1–2 years.
Can the NIHSS be used for all stroke types?
The NIHSS was originally validated for ischemic stroke and is most reliable in this population. It is also commonly used in hemorrhagic stroke (intracerebral hemorrhage and subarachnoid hemorrhage) as a measure of neurological severity. However, certain stroke types and locations may present with deficits not well captured by the NIHSS. For example, posterior circulation strokes may have disproportionate ataxia, vertigo, or cranial nerve findings that are not fully reflected in the total score. Similarly, right hemisphere strokes may have more neglect and left hemisphere strokes more aphasia, but these differences are captured by individual items.
How often should the NIHSS be repeated?
The frequency of NIHSS reassessment depends on the clinical setting. In acute stroke care, many protocols recommend reassessment at 24 hours post-treatment, at day 7 or discharge, and at 90 days for outcome assessment in clinical trials. During the acute phase, serial assessments may be performed more frequently (e.g., every 4–6 hours) to detect early neurological deterioration or improvement. A 4-point change in NIHSS score is generally considered clinically significant. In clinical trials, the NIHSS is often assessed at baseline, 24 hours, day 7 (or discharge), and day 90.
⚠️ Important Medical Disclaimer: This NIH Stroke Scale Calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. The NIHSS should only be administered by trained healthcare professionals who have completed NIHSS certification. Always consult a qualified medical provider for stroke assessment and management decisions. Do not delay seeking emergency medical care based on the results from this calculator.