Sleeping Less Than Seven Hours a Night May Shorten Your Life, New Study Warns
A growing body of research is raising the alarm about how insufficient sleep may be quietly cutting years off people’s lives, with a major new study showing that regularly sleeping less than seven hours per night is strongly linked to lower life expectancy. While many people already know that lack of sleep leaves them feeling groggy the next day, scientists now say the consequences go far deeper — affecting long-term health, disease risk, and overall longevity.
The study, conducted by researchers at a major U.S. university and published in a peer-reviewed sleep science journal, analyzed comprehensive data from more than 3,000 counties across the United States over a multi-year period. By comparing self-reported sleep duration with county-level life-expectancy statistics collected between 2019 and 2025, researchers uncovered a striking pattern: communities where a larger proportion of residents regularly slept fewer than seven hours a night tended to have lower average lifespans than those where more people met the recommended sleep threshold. These associations held true regardless of income, access to healthcare, or whether an area was urban or rural.
Although the research does not prove that short sleep directly causes premature death, the strength of the relationship rivals that of well-known lifestyle risk factors. In fact, when researchers examined multiple behaviors and health variables simultaneously — including diet, physical activity, obesity and diabetes — insufficient sleep ranked as one of the most powerful predictors of shorter life expectancy, with only smoking showing a stronger linkage.
Experts say the findings build on decades of science showing that sleep supports nearly every system in the body. Sleep is critical for heart health, immune function, metabolic regulation, and brain performance. Chronic sleep loss triggers stress responses, increases inflammation, disrupts hormone balance, and impairs the body’s ability to repair itself, all of which can contribute to the development of serious chronic diseases that shorten life.
Beyond life‐and‐death outcomes, insufficient sleep has been linked in other studies to a range of health risks. People who regularly sleep less than seven hours per night are more likely to have high blood pressure, poor blood sugar control, and impaired immune function. Long-term sleep debt is also associated with an elevated risk for cardiovascular disease, diabetes, obesity, cognitive decline, and mental health disorders.
The American Sleep Foundation and other public health authorities recommend that most adults aim for seven to nine hours of sleep each night to support optimal health. Yet a large portion of adults fall short of that target. Surveys indicate that over a third of U.S. adults consistently fail to get seven hours of sleep, often due to lifestyle demands, work schedules, stress, screen exposure, and other modern pressures.
Sleep experts emphasize that sleep isn’t a luxury but a fundamental biological requirement, as important as diet and exercise. Chronic sleep deprivation doesn’t only make people tired; it increases all-cause mortality risk and contributes to the development and progression of deadly diseases.
What makes sleep so vital is its role in restoring the body and brain. During sleep, tissues rebuild, immune cells regenerate, and metabolic processes reset. The brain clears out waste products through the glymphatic system, a cleaning mechanism that is far more active during sleep than wakefulness. Without adequate rest, these processes falter, and damage can accumulate over time.
In addition to total hours slept, consistency matters. Other research shows that irregular sleep patterns — sleeping different amounts on different nights or shifting bedtimes frequently — are linked to shorter lifespans and poorer health outcomes, even when average sleep duration appears adequate. Regularity helps synchronize the body’s internal clock, supports hormone balance, and improves sleep quality.
While sleeping significantly more than nine hours regularly has also been connected with increased mortality in some research, the consensus remains that consistently failing to reach the seven-hour threshold is one of the more widespread and modifiable risk factors for reduced life expectancy in developed countries.
Importantly, the new study’s findings suggest that sleep should be a public health priority. Communities and policymakers could consider initiatives to promote healthy sleep habits — from employer policies that discourage excessively long work hours to school start times aligned with adolescent sleep needs, to public campaigns that educate people about sleep hygiene.
Individuals also have a role to play. Experts recommend practical steps to improve sleep, such as establishing a consistent bedtime routine, limiting screen exposure in the evening, creating a dark and quiet sleep environment, avoiding caffeine and heavy meals close to bedtime, and setting regular sleep and wake times.
For many adults, small changes — like going to bed 15 minutes earlier each night — can gradually add up to significant improvements in total sleep. Over time, these adjustments may not only boost daily functioning and mood but also contribute to better long-term health and potentially even a longer life.
With mounting evidence connecting sleep to longevity and health outcomes, ignoring insufficient sleep is no longer just a matter of feeling tired — it is a behavior with real consequences. Both individuals and communities would benefit from taking sleep seriously, recognizing that restful nights are an essential foundation for a longer, healthier life.
