Some people seemingly can’t get enough z’s. They might sleep for hours on end and still feel exhausted while others around them are waking up refreshed.
Getting extended hours of shut-eye seems like a gift rather than a curse, but there are some caveats. Sleeping in on a Saturday morning is an indulgence. Regularly sleeping 10 or more hours, however, may be an indication of something serious, especially if you’re still in desperate need of a midday nap.
“Most adults need seven to eight and a half hours of sleep,” Ronald Chervin, director of the Sleep Disorders Center at the University of Michigan, told HuffPost. “But if someone is sleeping unusually large amounts and still feels unrefreshed, that would be a reason to see a sleep physician.”
We asked the experts why some people hit the snooze button a little more regularly than others and what you can do if your unconscious hours are becoming a problem. Here’s what you need to know:
1. Needing more sleep might be built into your DNA
Research suggests genetics may play a role in why some people need those extra hours.
“Some are just predisposed to require more sleep. There’s not much we can do individually about our genetics,” Chervin said. “But we can do things about other factors that control how much we sleep, like regularity of bedtime and rise time.”
Adolescents are also generally prone to sleep longer and have a harder time waking up.
“It’s believed to be associated with a lengthening of inner circadian clocks, which normally control sleep, though habits play a role,” Chervin continued. So if your parents ever gave you a hard time about sleeping in late as a teen, you weren’t entirely at fault for those extra hours.
2. It might be a sign of a sleep disorder
You might be suffering from one of multiple sleep disorders, some of which result in a late start to your day. One is hypersomnia, or “sleep drunkenness,” which is nicknamed for its side effect of disorientation.
“A person with hypersomnia can’t get out of bed and 10 hours is never enough. They can take two- or three-hour naps and still feel the need to sleep,” said Emmanuel H. During, a neurologist and psychiatrist specializing in sleep medicine at Stanford University. “You can develop it at any age and we don’t fully understand its cause.”
A rare neurological disorder called Kleine-Levin syndrome, or “sleeping beauty syndrome,” can also induce an extreme need for sleep.
“They can spend 15 or 20 hours in bed for days or weeks at a time and only get up to use the bathroom or eat,” Chervin said. Research suggests the syndrome affects only one in a million individuals.
3. Your mental health might be a culprit
“Long sleep is one way that depression can manifest itself. A person can sleep more and feel sleepy throughout the day and rest 10 or 11 hours regularly,” During said.
Research shows there may be a link between depression and sleep disorders, frequently associated with cases of insomnia and hypersomnia. Certain medications used to treat conditions can also result in a general grogginess and longer sleep. It’s best to consult a doctor if you suspect a medication is the culprit.
4. An underlying medical condition might be to blame
Traumatic brain injuries can result in long sleeping patterns, During said. One study found that people who recently suffered traumatic brain injuries often slept much more than healthy volunteers. Sleep is also strongly linked to recovery for trauma victims, with research showing that brain function improved with sufficient sleep.
5. You’re severely lacking in sleep
If you’re prone to pulling an all-nighter or two, it’s common to sleep longer when given the opportunity. Fortunately, this is more a consequence of habit rather than an indication of something deeper, as long as it’s not a natural pattern, During said. That said, compensating for sleep debt through sporadic naps or longer sleep does not always produce the desired effect.
People tend to view sleep as a fund so they try to sleep less one night and think they can make up for it with a long snooze later, Chervin said. “But you won’t always make up hours that you missed,” he added.
Research shows that sleeping 10 hours when chronically deprived only initially boosted performance before a rapid drop, calling into question the effectiveness of catching those extra z’s.
Bottom line: If you feel consistently fatigued despite getting enough sleep, check in with a doctor, During said. But if you typically wake up feeling refreshed and ready to take the day on, sleeping more every once in a while won’t harm you. After all, you spend a third of your life asleep — what’s a few extra hours?
This story has been updated to include a more specific statistic and link to research about the prevalence of Kleine-Levin syndrome.