Printed on 2/13/2026
For informational purposes only. This is not medical advice.
The National Institutes of Health Stroke Scale (NIHSS) is a systematic assessment tool that provides a quantitative measure of stroke-related neurological deficit. It evaluates 15 items including level of consciousness, gaze, visual fields, facial palsy, motor function, limb ataxia, sensory, language, dysarthria, and extinction/inattention. Scores range from 0 (no deficit) to 42 (maximum deficit).
Formula: NIHSS = sum of 15 items (range 0–42)
Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.
The NIH Stroke Scale is a 15-item neurological examination scale used to evaluate the effect of acute stroke on consciousness, language, neglect, visual fields, eye movement, motor strength, ataxia, dysarthria, and sensory loss. Scores range from 0 to 42.
NIHSS 0: no stroke symptoms. 1–4: minor stroke — may not require thrombolysis. 5–15: moderate stroke — generally eligible for IV tPA within 4.5 hours. 16–20: moderate-severe — consider IV tPA and thrombectomy. 21–42: severe stroke — consider thrombectomy.
IV tPA (alteplase) is typically considered for NIHSS ≥4 within 4.5 hours of symptom onset. Mechanical thrombectomy may be beneficial for large vessel occlusions with NIHSS ≥6 up to 24 hours in selected patients. Lower scores may still warrant treatment based on disabling symptoms.
The NIHSS has good inter-rater reliability when administered by trained personnel. Formal certification is required for clinical trial use and is recommended for clinical practice. The scale takes approximately 5–8 minutes to administer.