Study Finds Insomnia Increases Stroke Risk and Hospitalization Odds

The review synthesizes evidence across various health outcomes, revealing associations between insomnia and increased rates of depression, suicidal behavior, and a potential link to dementia, particularly Alzheimer’s disease. This adds to the growing body of evidence indicating that insomnia may entail health risks beyond just poor sleep quality and daytime functioning. Insomnia is characterized by difficulty in falling or staying asleep, leading to impaired daytime performance despite adequate opportunities for rest. It is estimated that 22% of the general population meets international diagnostic criteria for insomnia.

Luca Vignatelli, the lead author from the IRCCS Istituto delle Scienze Neurologiche di Bologna in Italy, stated that insomnia should be viewed as a warning signal regarding brain and mental health. He noted that individuals experiencing insomnia face heightened risks for conditions like dementia and stroke, suggesting that insomnia management should be integral to comprehensive health strategies aimed at reducing such risks.

To assess the broader health impacts of insomnia, the researchers reviewed two major medical databases, MEDLINE and EMBASE, up to August 2025. They incorporated findings from existing systematic reviews along with three new systematic reviews focusing on stroke, workplace injuries, and hospitalizations.

The analysis identified nine relevant studies concerning stroke, with six included in the meta-analysis, comprising over 1.3 million participants. Results indicated that individuals with insomnia showed a 26% higher risk of stroke (HR 1.26; 95% CI 1.05–1.53), although variability existed among different studies. Five studies addressed hospitalization, with three included in the analysis. The results showed an increase of 28% in hospitalization odds for people with insomnia (OR 1.28; 95% CI 1.14–1.43).

Beyond stroke and hospitalization, insomnia was associated with several mental health outcomes. While most reviews indicated a connection to all-cause dementia, results were inconsistent among studies. There was, however, a stronger consensus regarding Alzheimer's disease, and mixed findings related to vascular dementia.

The researchers caution that their findings should be understood in light of varying definitions of insomnia used across studies and the limited examination of sleep medication impact. They emphasize that the study identifies associations but does not confirm causation. Nevertheless, the results advocate for increased focus on insomnia within clinical care and the promotion of sleep hygiene and sleep disorder awareness in public health initiatives.

Stefan Seidel, another study author, remarked that discussions around brain health should encompass sleep issues at all ages, advocating for increased awareness of insomnia treatment and the integration of sleep health into community health promotion efforts.