This review comprehensively analyzes the molecular mechanisms and pathophysiological significance of voltage-gated sodium channels, with particular emphasis on elucidating the molecular-action mechanisms of the distinct subtypes of these channels, including Nav1.1, Nav1.2, and Nav1.6, across various neurological disorders such as familial hemiplegic migraine, epilepsy, autism spectrum disorder, and retinal dysfunction. Here, SCN2A is linked to epilepsy.