Study details

According to NIH, insomnia makes it difficult to fall asleep, stay asleep, or get good quality sleep. It's the most common sleep disorder in the United States, and a previous meta-analysis estimated that insomnia meeting international diagnostic criteria affects around 22% of the general population.

For the analysis, researchers searched two major medical research databases — MEDLINE and EMBASE — up to August 2025 for studies on the health impact of insomnia. They combined evidence from various existing systematic reviews with three new reviews of primary studies on stroke, occupational injuries, and hospitalization. Overall, the review analyzed around 20 studies, which included more than 1.3 million participants.

The researchers found that insomnia was linked to a 26% increased risk of stroke and a 28% increased risk of being hospitalized for any reason. They also found that individuals with insomnia were more likely to have depression and attempted suicide compared to those without insomnia.

In addition, the researchers found a connection between insomnia and dementia, especially Alzheimer's disease. According to NIH, sleep has been shown to play an important role in clearing the waste products linked to Alzheimer's disease and impaired brain function.

"When you sleep, that's when your brain takes out the trash," said Thanuja Hamilton, a board-certified sleep medicine physician at Advocare. "If you're not getting good quality sleep or enough of it, then you're going to have an excess buildup, increasing that risk of dementia down the line."

Discussion

The researchers noted the findings only show associations between the various conditions and insomnia and don't prove that insomnia directly causes the health problems the analysis examined.

"I would like to emphasize that people should not be frightened by these results. An increased risk at the population level does not mean that an individual with insomnia will develop dementia, depression or have a stroke," said Stefan Seidel, one of the study authors and a professor of neurology at the Medical University of Vienna. "Instead, the findings give us another reason to take persistent sleep problems seriously, identify possible underlying causes and provide evidence-based treatment when appropriate."

Experts said that sleep issues, including insomnia, are often overlooked when addressing mental health concerns.

Vignatelli added that sleep should become a more routine part of conversations with doctors about overall health.

"Sleep should be a topic to discuss with your doctor when talking about health, at any age," he said. "We need to raise public awareness about insomnia and its treatment and ensure that sleep is included in health promotion programs in our communities, schools, and workplaces."

How to improve your sleep

According to health experts, habits like making your bed each day, keeping your bedroom cooler, and turning off the lights before bed can help improve your sleep.

They also said one of the most important healthy sleep habits is maintaining a consistent sleep schedule. "Our circadian rhythm, our internal clock, it likes consistency," Hamilton said. "If you are inconsistent with your sleep, then you confuse your brain. It doesn't know when to start sleep or when to stop sleep."

Turning off distractions like the TV or your phone around 30 to 60 minutes before bedtime and not consuming coffee or alcohol late at night can also help you sleep better.

"You go down that rabbit hole when you get on the phone," Hamilton said. "It might distract you, but it's not relaxing you."

People who have insomnia can also become anxious about whether they'll be able to sleep, which can potentially make the issue worse. "The harder you try to sleep when you have insomnia, the harder it is to sleep," Hamilton said.

Generally, the first treatment for long-term insomnia is cognitive behavioral therapy (CBT), which focuses on changing thoughts and behaviors that can interfere with sleep and can include techniques like adjusting sleep schedules and limiting the amount of time spent awake in bed, according to NIH.

"The gold standard of treatment for insomnia is CBT, but it's difficult and it's time-consuming and it's a lot of effort, especially for someone with chronic insomnia," Hamilton said. "But it is worth it."