Is too much sleep bad? How oversleeping could signal something is wrong

Sleeping in once and a while is fine, but getting nine or more hours of sleep regularly could damage your health. ALPA PROD/Shutterstock
  • Most healthy adults should be getting 7-9 hours of sleep each night.
  • More sleep may be necessary for these limited groups: people who are sick, children, teens, or those with an underlying medical condition.
  • Oversleeping has been linked to a number of negative health outcomes including heart disease, obesity, diabetes, and depression.
  • This article was medically reviewed by Raj Dasgupta MD, FACP, FCCP, FAASM, Assistant Professor of Clinical Medicine with the Division of Pulmonary, Critical Care & Sleep Medicine University at Southern California (USC).
  • Visit Insider’s homepage for more stories.

Sleeping in on the weekends is a luxury many of us look forward to all week long. And while the occasional long sleep is generally nothing to worry about, oversleeping several days a week could be a sign that something more serious is going on.

Here’s what you need to know about getting too much sleep.

How much sleep is too much

Unfortunately, there is no easy answer to what counts as oversleeping. Roy Raymann, PhD Chief Scientific Officer at SleepScore Labs, tells Insider that it depends on many factors like genetics, age, health, fitness level, activity, and the amount of stress a person is under.

For most adults, he says: “If you sleep more than nine hours a day, several days a week, and still feel tired during the day, you might be oversleeping.”

However, Raymann also points out that sleeping more than nine hours on a regular basis is acceptable for young adults, people recovering from illness, or people recovering from several days in a row with less than adequate sleep.

The right amount of sleep to get

Not sure how much sleep you actually need? The Journal of Clinical Sleep Medicine (JCSM) says adults, aged 18 to 60, should get seven to nine hours of sleep each night on a regular basis.

“That said, only a few people can do with less than five hours a night, without negative health and wellbeing consequences,” says Raymann. Also, kids need more sleep than adults. Here’s how long each age group should sleep each night, according to the CDC.

Infants (4 months to 12 months)

12-16 hours

Toddler (1-2 years)

11-14 hours

Pre-school (3-5 years)

10-13 hours

School Age (6-12 years)

9-12 hours

Teenagers (13-17 years)

8-10 hours

Adults (18-60 years)

7 or more hours

Adults (61-64 years)

7-9 hours

Adults (65+ years)

7-8 hours

It’s important to note, says Raymann, that the hours of sleep are not equal to the amount of time spent in bed with the lights off and your eyes closed. To get the recommended minimum of seven hours each night, he says most people need to be in bed for almost eight hours.

The negative consequences of oversleeping

According to Johns Hopkins Medicine, the health problems associated with oversleeping are:

  • Type 2 diabetes
  • Heart disease
  • Obesity
  • Depression
  • Headaches
  • Greater risk of dying from a medical condition

But Raymann points out that these conditions might be a result of a chicken-and-egg type of problem. It’s hard for researchers to determine which came first: Did the underlying disease cause the oversleeping or does oversleeping trigger the disease or medical condition?

Studies have also found there are links between oversleeping and unfavourable health outcomes. According to a 2014 survey published in PLOS ONE, long sleepers that slept over 10 hours a day had a higher body mass index (BMI). These long sleepers were also found to have a higher rate of depression.

In short, it’s best to stick to the CDC’s recommended sleep guide and consult a doctor if you’re regularly sleeping more than 9 hours a day.

Related health explainers: