Insomnia and stroke risk: what a large new review found
Insomnia and stroke risk: a review of over 1.3 million people linked insomnia to a 26% higher stroke risk vs. those without it. What that means.
The 30-second summary
- A review covering more than 1.3 million people found that insomnia was linked to a 26% higher risk of stroke, compared with people without insomnia.
- Insomnia was also linked to 28% higher odds of hospital admission than in people without it, and to depression, with evidence suggesting a link to dementia, especially Alzheimer's.
- The studies were observational: they show a link, not that insomnia causes these problems.
Is there a link between insomnia and stroke risk? Yes, according to a new review: people with insomnia had a 26% higher risk of stroke than people without it. But this shows a link, not proof that insomnia causes stroke.
The review, published in Sleep Medicine Reviews in 2026, brought together evidence on seven health outcomes from studies with more than 1.3 million participants. Here is what the researchers found, how they did it, and what the results can't tell us.
What did researchers find?
People with insomnia had a 26% higher risk of stroke than people without it. But the size of this link varied a lot from one study to another. People with insomnia also had 28% higher odds of being admitted to hospital for any reason, compared with people without it.
Looking at the wider evidence, insomnia was linked to depression and suicidal behaviors. For dementia, most reviews found a link with insomnia, but results were not consistent across all studies. The evidence was more consistent for Alzheimer's disease, and mixed for vascular dementia.
Based on this, the researchers say insomnia should be recognized as an important marker of brain, mental and general health. Lead author Luca Vignatelli, of the Institute of Neurological Sciences of Bologna in Italy, said insomnia deserves attention as a warning sign of the state of brain and mental health.
How was the study done?
This is an umbrella review: research that pulls together earlier reviews and studies instead of running a new experiment. The team searched two large medical research databases, MEDLINE and EMBASE, up to August 2025. They combined existing systematic reviews with three new systematic reviews on stroke, work injuries and hospital admission. For stroke, they found nine suitable studies and pooled six in a combined statistical analysis. For hospital admission, five studies looked at the question and three were pooled. The pooled studies were observational: they observed people without changing anything about their sleep.
We rate evidence by study design, not by how exciting the result is. How we rate evidence
What does it mean for you?
The main takeaway: insomnia may be a signal about your brain and mental health, not just an annoying night. It is also common: an earlier analysis estimated that about 22% of the general population has insomnia that meets international diagnostic criteria.
At the same time, 26% is a relative increase compared with people without insomnia; it does not mean everyone with insomnia will have a stroke. If insomnia keeps bothering you, talking to your doctor about it is a reasonable step. The researchers also call for sleep to be part of health programs in communities, schools and workplaces.
But keep in mind
- The pooled studies were observational: they show a link between insomnia and stroke, not that insomnia causes it. The authors stress this themselves.
- Studies defined insomnia in different ways, and the size of the link with stroke varied a lot between them.
- Sleep medication use was not adequately taken into account, so its role in the results is unclear.
- The stroke result rests on six pooled studies and the hospital result on three, and dementia findings were not consistent across all studies.
FAQ
Can insomnia cause stroke?
This review can't show that. It found that people with insomnia had a 26% higher risk of stroke than people without it, but the studies were observational and show a link, not a cause.
What does insomnia do to the brain?
In this review, insomnia was linked to stroke and depression, and evidence suggested a link with dementia, especially Alzheimer's disease. These are associations, not proven effects.
Is insomnia the same as lack of sleep?
Not quite. Insomnia means trouble falling or staying asleep, with problems functioning during the day, even when you have enough chance to sleep. This review studied insomnia, not short sleep from lack of time.
How common is insomnia?
An earlier analysis estimated that about 22% of the general population has insomnia that meets international diagnostic criteria.
Sources
- 1Insomnia as risk factor for brain, mental and general health consequences: an umbrella systematic reviewSleep Medicine Reviews · 2026
- 2Insomnia linked to higher risk of strokeMedical Xpress · 2026
These are the original sources; we only explain them. Read them yourself.
Science information for education only; it does not replace medical advice.
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