The NIHSS score, short for National Institutes of Health Stroke Scale, quantifies the degree of neurologic impairment to assess stroke severity. The NIHSS score divides the neurologic examination into multiple items, and the results of each item have a corresponding score for the scale. By examining the patient’s neurologic function, it is possible to quantify the degree of impairment of each item of neurologic function one by one. Items include level of consciousness, level of consciousness questioning, level of consciousness instructions, gaze, visual field, facial palsy, upper and lower limb movement, limb ataxia, sensation, language, dysarthria, and neglect, each with detailed scoring rules and details. The total score of NIHSS score ranges from 0 to 42, the higher the score, the more serious the neurological impairment, i.e., the more serious the degree of stroke.The NIHSS score usually requires a professional doctor to evaluate. Prompt medical attention and standardized treatment are recommended.