For years, we’ve been told to get more sleep. But what if getting too much of it is quietly harming us? A new study is turning the conventional wisdom on its head, revealing that sleeping more than nine hours a night may actually be riskier to your health than sleeping too little.
More Sleep, More Risk?
Sleep is essential — it heals, repairs, and restores both body and mind. But a comprehensive new analysis by researchers at the University of Oklahoma suggests that excessive sleep could signal serious underlying health issues and even raise the risk of premature death.
The research pooled data from 79 studies worldwide, each tracking participants for at least one year. The key takeaway? People who slept more than nine hours per night were found to have a 34% higher risk of dying during the study period, compared to those who slept between seven and eight hours.
By contrast, those who slept less than seven hours had a 14% increased risk — still significant, but notably lower than the oversleeping group.
What Could Be Causing It?
These findings don’t suggest that long sleep hours cause death, but they do serve as a red flag. Researchers believe excessive sleep may reflect deeper health problems like:
- Chronic inflammation
- Undiagnosed cardiovascular issues
- Depression or anxiety
- Metabolic disorders
Dr. Chun Shing Kwok, a leading researcher behind similar studies, pointed out that prolonged sleep might be a “marker of elevated cardiovascular risk,” not the source. He added that poor sleep quality, whether too little or too much, was linked to a 44% increased risk of developing heart disease.
Looking Back: Patterns and Precedents
This isn’t the first time scientists have warned about the dangers of too much sleep. A 2018 meta-study, based on 74 previous studies, found almost identical risks, including a 30% higher mortality risk for those sleeping 10 hours or more.
These consistent results across different populations and time periods make the trend hard to ignore.
Then, What’s the Right Amount?
The “sweet spot” remains 7 to 9 hours per night for most adults. Teenagers may need a bit more — around 8 to 10 hours — while seniors typically fall within the same range but may require daytime naps.
Importantly, quality matters as much as quantity. Irregular sleep, poor bedtime habits, or frequent interruptions can be just as damaging as oversleeping.
When to Worry About Sleeping Too Much
Oversleeping occasionally—like after a long work week or illness—isn’t usually a problem. But consistently needing over nine hours, especially if you still wake up tired, could be a symptom worth investigating.
Experts advise that persistent oversleeping, combined with fatigue, low energy, or brain fog, might indicate:
- Sleep apnea
- Thyroid issues
- Mental health conditions
- Vitamin deficiencies
If that sounds familiar, it’s a good idea to talk with a healthcare provider.
The message here isn’t to fear your weekend lie-in, but to be mindful. Sleep is a window into your body’s overall health. Getting just the right amount—consistently and with good quality—might be more powerful than we think. Too much of a good thing, in this case, may actually be bad for you.
