One of the joys of adulthood is being able to go to bed whenever you want. But new research is making the case for viewing a consistent bedtime as non-negotiable for your health as getting in seven-plus hours.
The study, which was published in the journal BMC Cardiovascular Disorders, found that keeping irregular bedtimes dramatically raises the risk of major adverse cardiovascular events like heart attack and stroke.
There’s no need to panic if you stay up late here and there to catch up with friends or your Netflix list. But doctors say this is important information to take into account if your bedtime is consistently all over the map. Here’s why.
The study found an important link between irregular bedtimes and serious heart health issues.
For the study, researchers analyzed data from 3,321 people from a long-term study in Finland. The participants wore accelerometers (movement trackers) starting from 2012 to 2014 up to 2023. The researchers looked at the participants’ sleep timing, bedtime consistency, and when they woke up, among other things.
The researchers discovered that 4% of the study participants experienced a major adverse cardiovascular event (MACE) like heart attack, stroke, hospitalization for heart failure, or death from a cardiovascular reason during the study period. In people who slept less than the median amount of the group, which was nearly eight hours, having an irregular bedtime was linked to double the risk of a major cardiovascular event.
“Among the participants with sleep durations under eight hours, irregular sleep timing was a significant risk factor for MACEs,” the researchers wrote in the study’s conclusion. “These findings highlight the importance of consistent sleep behavior, particularly regular bedtimes, as a potential target for health promotion.”
Research suggests that about 40% of American adults don’t even get the recommended seven-plus hours of sleep a night, making this information plenty of people can use. A recent Gallup poll suggests that only 26% of Americans get eight or more hours of sleep each night.
A growing body of research has focused on sleep irregularity.
For years, researchers have zeroed in on how much sleep people consistently get at night. But there’s been a rise in research that finds variation between how much sleep you get from night to night matters too.
One 2025 study published in the Journal of the American Heart Association linked inconsistent sleep patterns with “consistently higher risks” for major cardiovascular disease events like heart attack and stroke.
On the flip side, a 2023 study published in the journal Sleep linked consistent bedtimes and wake times with a 48% lower risk of dying from any cause during the nearly eight-year study period. “Sleep regularity may be a simple, effective target for improving general health and survival,” the researchers wrote in the conclusion.
There are likely a few things behind this.
The study didn’t dive into why there’s an association between irregular bedtimes and a higher risk of cardiovascular events—it just found a link. Still, doctors have a few theories.
One is that this could mess with “sleep pressure,” or the body’s natural drive to sleep, Sarathi Bhattacharyya, MD, medical director of MemorialCare Sleep Disorders Center at Long Beach Medical Center in Long Beach, California, tells SELF.
“The human circadian rhythm works on a timed cycle, and if sleep pressure accumulates but is ignored—i.e., staying up late—then the body’s period for recovery and hormone signaling gets disrupted,” Dr. Bhattacharyya explains. Beth Malow, MD, a neurologist and chief of the Division of Sleep Disorders at Vanderbilt Health, agrees. “When circadian rhythms are affected, it can lead to inflammation, increases in stress hormones, and changes in metabolism, like weight gain,” she tells SELF. “All of that can affect the heart in a negative way.”
Over time, this can lead to fluctuating blood pressure and heart rate, which is linked to long-term cardiovascular risk, Navjot Sobti, MD, interventional cardiologist at Northwell’s Northern Westchester Hospital and women’s health expert at Katz Institute for Women’s Health, tells SELF.
Also, when you’re chronically sleep deprived, regardless of when you go to bed, it can increase stress hormones in your body and increase the risk of cardiovascular issues, Dr. Bhattacharyya says. “In clinical practice, sleep doctors will often recommend a consistent wake time to help align the circadian rhythm to the day/night cycle of the Earth,” he says. “But promoting a consistent bedtime is important so that adequate sleep time can be achieved.”
Consistent sleep also encourages your cardiovascular system to “downregulate” and reset at night, which ultimately supports good cardiovascular health, W. Christopher Winter, MD, a neurologist and sleep medicine physician with Charlottesville Neurology and Sleep Medicine, tells SELF.
Having an irregular bedtime and sleep schedule can also throw off a range of elements linked to good heart health, Dr. Winter says. “Irregular sleep timing is closely tied with irregular exercise, irregular eating, etc., and that inconsistency can wildly disrupt metabolism, cognitive abilities, mood, endocrine functioning, neurological processing, and yes, cardiovascular health,” he says.
Ultimately, “it’s not just about how long you sleep, but how consistent your sleep timing is in a very real, physiologic way,” Dr. Sobti says. “Your circadian rhythm doesn’t need perfection; it needs consistency,” she adds.
How to set (and stick to) a bedtime.
Everyone’s ideal bedtime is slightly different, which is why Dr. Malow recommends listening to your body when it comes to figuring out the perfect bedtime for you. “Go to bed when you are feeling tired,” she says. “If you try to go to bed too early, your body may be too alert.” And, of course, if you go to bed too late, you’ll end up shortchanging your sleep.
You can also start with a standard wake time and work your way backward, if your schedule allows, Dr. Winter says. “Make that consistent,” he says. “Working back seven to eight hours from there is probably a good place to start in terms of a bedtime.”
While you’re at it, Dr. Malow recommends being careful of having caffeine or alcohol in the evening, or using screens too close to bedtime—all of those can throw your sleep out of whack.
Ultimately, Dr. Malow suggests just making it a point to create and stick with a bedtime that works for you. “Do your best to choose a consistent bedtime, even if you have to deviate from it some nights,” she says. Dr. Winter agrees. “It’s not about being perfect, but rather being better than you were before,” he says.
Related:
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- 6 Foods to Eat for Better Sleep
- I Went on a $1,700-a-Night Sleep Retreat
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