A systematic review and meta-analysis of 17 studies involving 7,696,920 patients found that insomnia symptoms were associated with an increased risk of ischemic stroke but not with overall or hemorrhagic stroke, while clinically diagnosed insomnia was associated with a higher risk of all stroke types. Findings varied by study design, with some analyses showing broader associations, and overall evidence ranged from high certainty for ischemic stroke risk with symptoms to moderate certainty for diagnosed insomnia.