Insomnia could significantly raise the risk of stroke and Alzheimer's, claims new study

Published: 05:55 EDT, 28 September 2026 | Updated: 06:06 EDT, 28 September 2026 Regularly struggling to fall asleep may raise the risk of stroke by more than a quarter, and increase a person's chances of developing Alzheimer's, research suggests.Insomnia, a common sleep disorder characterised by difficulty falling asleep or getting enough to feel refreshed, can have a significant impact on mood, memory and concentration. Up to a third of UK adults are thought to suffer from the condition, experiencing frequent disrupted sleep, though far fewer receive a formal diagnosis. Now, Italian researchers have linked the disorder to a 28 per cent increased risk of hospitalisation and a 26 per cent greater risk of stroke - highlighting the importance of recognising insomnia as a marker of brain health. 'Insomnia deserves attention as a warning sign of the status of brain and mental health,' said Dr Luca Vignatelli, a neurologist at the Institute of Neurological Sciences of Bologna, and study co-author. 'These findings show that someone with insomnia has an increased risk for dementia or stroke.' He added: 'Insomnia should be recognised and addressed as part of a wider approach to health to reduce the risk of developing such disorders.'The study - published in the journal Sleep Medicine Reviews - analysed health data from more than 1.3 million participants from two major medical research databases. Insomnia could increase the risk of stroke by more than a quarter, new research suggests Results showed that people with insomnia had a 26 per cent increased risk of stroke, although results varied between studies. Around 100,000 people suffer strokes each year in the UK, with the condition killing around 35,000. While the researchers did not offer a specific cause, previous studies have shown that chronic sleep deprivation is linked to high blood pressure, one of the biggest risk factors for stroke. Levels of C-reactive protein, a marker of inflammation, also rise when people do not get enough sleep - typically considered between seven and nine hours - putting added strain on the heart. The team also looked at three existing studies examining the link between hospitalisation and insomnia, and concluded people with insomnia are 28 per cent more likely to be admitted to hospital for any reason. Beyond this, the review - funded by the European Academy of Neurology - also linked insomnia with dementia and Alzheimer's disease. However, the researchers stressed the findings do not prove that insomnia causes stroke or cognitive decline, only that the conditions are linked. Nevertheless, they said the results support greater attention to sleep disturbances in clinical care and wider public health campaigns. 'Sleep should be part of the conversation about brain health at every age,' Professor Stefan Seidel, said. 'We need to raise awareness of insomnia and its treatment and make sure sleep is included in health promotion programmes in our communities, schools and workplaces.' Research has long shown that getting six to eight hours of sleep a night reduces the risk of several health conditions, including high blood pressure, dementia and stroke. During deep sleep, the brain clears away waste products that build up throughout the day. Scientists believe that consistently poor sleep may impair this process, potentially contributing to cognitive decline over time. A recent study analysing data from more than 95,000 UK adults even found that those who get more rapid eye movement (REM) sleep - the stage linked to dreaming - are at lower risk of 83 diseases. While insomnia can often be improved through better sleep hygiene - such as sleeping in a dark and quiet room, regular exercise, and avoiding screens before bed - sleep aids, cognitive behavioural therapy and sleeping pills can all help.