It’s a problem many of us would like to have, but as it turns out there is such a thing as getting too much sleep. For healthy adults ages 18 to 64, anywhere between seven and nine hours of shut-eye is normal, and recommended. The exact amount of sleep you need can vary according to your age, lifestyle and activity level, and can change during times of illness or stress.
What if I feel like I need more sleep?
Topping more than nine hours per night, however, can be a sign of an underlying issue, such as depression, diabetes or heart disease. Research from the Nurses' Health Study found that women who slept nine to 11 hours per night were 38 percent more likely to have coronary heart disease than those who slept for eight hours. The reason for the correlation between the two is still unknown.
A study from Quebec found that people who slept nine to 10 hours per night were 21 percent more likely to become obese over a six-year period that those who slept seven to eight hours, regardless of diet and exercise.
Oversleeping can also be the result of a medical condition known as hypersomnia. The disorder can have people zonked out for more than 10 hours a night, and can also cause extreme sleepiness during the day that isn’t alleviated by napping. Other symptoms of the condition include anxiety, low energy and poor memory, which are all linked to being sleep-deprived.
Oversleeping isn’t always linked to a medical problem, however. Prescription-med side effects can also be the cause.
How much sleep are we talking about exactly?
According to Kristen Knutson, who focuses on sleep research at the University of Chicago’s Department of Medicine, “If you’re sleeping 10 hours a night for months on end” a doctor would want to know why. Maybe you’re getting poor quality sleep or “you’re on the pathway to illness and your body is reacting by wanting you to sleep more.”
Obstructive sleep apnea, for instance, a condition that causes pauses in breathing during sleep and deprives the body of oxygen, can leave people exhausted and feeling like they need more time in bed because it interrupts the normal sleep cycle.
Should I worry if I’m sleeping more than nine hours every night?
Not necessarily. According to neurologist Alon Y. Avidan, who directs the UCLA Sleep Disorders Center, it can be “a genetic trait. Some people just need more than the average amount to function well the next day.” Though he says that only a small number fall into this category.
Adds Michael Breus, a specialist in sleep disorders, “If [someone] wakes up feeling refreshed, and they can work that into their schedule, then I’m not sure I care. But if they wake up after nine hours and don’t feel so hot” it’s worth talking to your doctor. For instance, if it’s a medication that’s tampering with your sleep, there may be an alternative.
For your part, sticking to a sleep schedule — going to bed and waking up at the same time every day — can help normalize sleep.