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Matthew J. Edlund M.D.
Matthew J. Edlund M.D.

Can Too Much Sleep Really Kill You?

How much sleep is too much?

Too long a night?
Source: Pixabay

Is it true that sleeping more than eight hours a night hastens your demise?

People certainly think so. Several years ago a national TV news reporter asked me if it was true, because after working shifts “I go home and sleep for 10 or more hours; will that shorten my life?” A recent article in Journal of the American Heart Association performed a meta-analysis following more than three million people and found those who slept nine hours a day died earlier than those who slept eight, with those sleeping 11 hours demonstrating an increased odds ratio risk of about 50%.

So does sleep need to be inside a “window” of seven to eight hours to obtain the best results? Or is long sleeping a marker for something else?

Who Sleeps Long

Keep people up all night and they’ll sleep more the next day. Fly from Beijing to Cincinnati and the discombobulation of jet lag plus the viral Superbowl of jet travel may occasion several days of prolonged slumber. Get a bad cold and you might sleep “all day.”

The body sleeps to recover and rebuild. Illness often provokes more sleep.

People with congestive heart failure often sleep long. So do those with sedating medications, which can include the many millions prescribed anti-hypertensive drugs. Patients with chronic pain or rheumatoid arthritis or lupus frequently sleep and sleep, as can adolescents with attention deficit disorder. People who are depressed—a growing part of the population, especially among the young—usually describe sleeping too little, too much, or both. Folks with bipolar disorder, especially when rapidly shifting through mood, may sleep two hours one day and 14 the next.

Among sleep disorders the classic causes of long sleep are narcolepsy and sleep apnea, where airflow is diminished and synchronization between heart and lung is deranged. Narcoleptics often come to clinical interest because people cannot get their heads off the pillow or involuntarily snooze at school or work.

Less remarked upon are the legions of insomniacs, who in population terms are frequent victims of “hypersomnia,” or sleeping too long. When people cannot sleep efficiently, they often spend more hours in bed. The natural idea is that if I’m only sleeping four hours when I want eight, if I spent a lot more time on a futon or mattress I’ll probably recover. The problem with this strategy is that it is often counterproductive. One of the most common treatments of insomnia is sleep restriction, based on the idea that time asleep equals time in bed. Then from a base of shorter but more solid sleep, people build up their capacity, effectively “relearning” how to sleep. This strategy also helps reset biological clocks that are often greatly upset by the common maneuvers insomniacs attempt to get more rest.

Another group that often sleeps long are people with obesity. As about 170 million American adults are overweight, this is a prominent and often neglected factor in long sleep. With almost any type of inflammation, people sleep longer, and people who are obese show increases in inflammatory markers in the body.

In sum, sleeping long is often related to acute and chronic illnesses, not to mention the stresses of school, work, and family. Lots of us sometimes sleep "too long."

Why Sleep?

It should not surprise that illness or stress of almost any kind can provoke long sleep. Sleep is like food. You need it to rebuild the body. Much of your body’s internal parts are rapidly depleted. They need regrowth and renovation. Sleep not only helps that renewal; it’s required.

Much of the renewal is informational, involving DNA, proteins, and cellular memory. Lots of it engages the rebuilding of tissues, like the face on our skin or the connective tissue in our muscles, that we witness firsthand. For much of the population, body rebuilding is optimal above seven hours given present work-life conditions. Some people sleep less because they are genetically built to do so. Functional hypomanics, whether they are Pablo Picasso or titans of tech, may do very well on three or four hours of sleep.

However, most of us need considerably more. Present clinical guidelines suggest seven to eight hours for most adults, because they perform better and look healthier when they get that amount. Adolescents need a couple hours more to learn and function well.

Loads of kids and adults don’t get their needed sleep. They wake to texts and photos. Prefer video games to slumber. Enjoy an alcoholic nightcap that “knocks them out” but then wakes them through the night.

When people don’t get enough sleep, they try recovery sleep. If people are starved, they want food. If people are sleep deprived, they attempt more sleep. Then they sleep long.

Bottom Line

Sleeping long is a symptom. By itself it does not kill people any more than beds kill people. Getting the right amount of sleep for you is a major factor in your performance, your health, your appearance—how you feel, moment to moment.

About the Author
Matthew J. Edlund M.D.

Matthew Edlund, M.D., researches rest, sleep, performance, and public health. He is the author of Healthy Without Health Insurance and The Power of Rest.

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