When You Oversleep, This Is What Happens To Your Heart Health

We all need a day every now and again when we shove the alarm clock back in the nightstand drawer and allow ourselves to sleep as late as our heart desires. Oversleeping on a regular basis, however, has been tied with an increased risk for several health conditions, including heart disease, according to 2010 research published in Sleep.

The National Heart, Lung, and Blood Institute reports that adults need approximately seven to nine hours of sleep each night. While experts caution about the health problems associated with a lack of sleep (particularly those pertaining to teens who don't get enough sleep), similar risks also appear to exist for people getting one too many hours of shut-eye. In the survey research, researchers analyzed self-reported data from more than 30,000 adults from the 2005 National Health Interview Survey. The survey questions pertained to participants' health status and average sleep duration in a 24-hour period. The findings showed that while adults who received five or fewer hours of sleep nightly were at an increased risk for cardiovascular disease, so were those who reported sleeping nine or more hours each night. More specifically, longer sleep durations were found to be linked with stroke and myocardial infarction (heart attack).

Even if you're someone who enjoys a daily workout, doesn't smoke, and has no family history of heart disease, 2019 research findings published in the Journal of the American College of Cardiology show that healthy lifestyle habits may not be enough to ward off your risk for heart attack if you're undersleeping or oversleeping. 

Over the course of seven years, researchers followed up with 461,000 middle-aged and older adults from UK Biobank who had no history of heart attack to find out that those who snoozed for over nine hours a night were at a 34% increased risk of heart attack. Sleeping for ten hours each night was found to double their risk of heart attack. Findings were slightly different, however, for people who were genetically predisposed to cardiovascular disease. Instead, the risk of heart attack dropped by 18% in these individuals, who reported sleeping between six and nine hours a night. 

One proposed theory as to why this relationship exists is that oversleeping may promote inflammation in the body. Inflammation is a potential contributing factor to heart disease.

Not all studies examining the connection between sleep and heart disease risk have had the same outcomes, however. Researchers from a 2018 study published in the Journal of Clinical Sleep Medicine involving over 60,000 adults at least 40 years of age analyzed sleep duration and sleep quality as well as numerous outside factors in relation to coronary heart disease risk. While a lack of sleep and poor sleep quality were linked with greater susceptibility to coronary heart disease, the connection between oversleeping and coronary heart disease risk was not deemed statistically significant.

Oversleeping has proven to be multifaceted, however, with certain mental health issues and lower socioeconomic status having been identified as two influencing factors that may also play a role in the potential relationship between longer sleep duration and heart disease risk (per WebMD). Oversleeping may also be related to certain health conditions, such as hypersomnia or obstructive sleep apnea. The Sleep Foundation also highlights diabetes, chronic pain, obesity, and hypothyroidism as other potential causes of oversleeping. 

If you find that you're consistently sleeping through your alarm, talk to your doctor about whether oversleeping may potentially be related to an underlying health condition.