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Can You Die From Lack of Sleep?The dangers of being really, really tired.

By Brian PalmerPosted Monday, May 11, 2009, at 7:35 PM ET

Sleeping detaineesCIA interrogators at Guantanamo Bay subjected dozens of detainees to sleep deprivation, shackling the prisoners in a standing position for up to 11 days at a time. Recently released Justice Department memorandums claim sleep deprivation studies show that "surprisingly, little seem[s] to go wrong with the subjects physically." Wait, is it really safe to go without sleep?

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No—extended bouts of sleeplessness can cause an array of physical symptoms and might eventually kill you. The effects begin within the first 24 hours of sleep deprivation. First, the body undergoes subtle hormonal changes—cortisol and TSH levels increase, leading to a rise in blood pressure. A day or two later, it stops metabolizing glucose properly, creating carbohydrate cravings. (This phenomenon may have gone unnoticed among the detainees, who were already on a calorie-restricted diet.) A person's body temperature will also drop, and his or her immune response becomes somewhat suppressed. All of these physiological changes are reversible, though—take a nap, and you'll be on the road back to normal.

Related in Slate

Amanda Schaffer discussed why people sleep. William Saletan reported on the military's sleep-reduction program. David Plotz tried a drug for the chronically sleep-deprived. Seth Stevenson tested over-the-counter sleep aids.

It's possible that given enough time, sleep deprivation can kill you. While no human being is known to have died from staying awake, animal research strongly suggests it could happen. In the 1980s, a University of Chicago researcher named Allan Rechtschaffen conducted a series of groundbreaking experiments on rats. After 32 days of total sleep deprivation, all the rats were dead. Curiously, researchers still do not agree on the cause of death. It's possible that the rats' body temperature dropped so much that they succumbed to hypothermia. Another theory posits that the rats' immune systems became so depressed that bacteria normally sequestered in their intestines spread throughout their bodies—though Rechtschaffen counters that his rats perished even when they were administered antibiotics. A third explanation points to some evidence of brain damage among the sleep-deprived rats. It's also possible that extreme levels of stress contributed to the rats' demise.

There's every reason to believe that humans would experience the same end result if they were kept awake for long enough. Our knowledge of prolonged, complete sleep deprivation in humans is limited because intolerable psychological effects such as hallucination and paranoia take hold long before the more severe physical symptoms. Most human studies involve no more than two to three days of complete deprivation or a week of partial sleep deficits. Data on more prolonged sleep deprivation come from anecdotes, animal research, or surveys of chronically sleep-deprived groups like medical residents.

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Explainer thanks Charles A. Czeisler of Harvard Medical School and Brigham and Women's Hospital, James B. Maas of Cornell University, Amita Sehgal of the University of Pennsylvania, and Jerry Siegel of UCLA.

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Brian Palmer is a freelance writer living in New York City. He can be reached at .

Photograph of sleeping detainee by Jose Cabezas/AFP/Getty Images.

COMMENTS

Brian Palmer's article states that "no human being is known to have died from staying awake...", but that's not true. People who have a very rare genetic prion disease called Fatal Familial Insomnia always die from staying awake. Those who have it are struck in middle age, are never able to sleep again, and die between six and 18 months later. One family in Venice, Italy, has records of insomnia deaths that go back more than 200 years.

It's really rare, documented in only about 40 families worldwide, but always fatal.

-- emshinn
(To reply, click here)

That's a great point, and thanks for bringing it up.

At this time, researchers simply aren't sure what kills patients with Fatal Familial Insomnia.

Two factors suggest that the cause of death may not be as simple as staying awake too long. First, FFI patients exhibit certain muscular symptoms that aren't typical in most sleep deprivation sufferers. Second, other prion diseases (such as Kuru and Creutzfeldt-Jakob) tend to kill in approximately the same amount of time as FFI after appearance of symptoms.

Further complicating the issue is that researchers don't agree on the exact cause of death in animals who have died in sleep deprivation studies. Until we can precisely define the "signature" of death by sleep deprivation, it is impossible to say that an FFI patient has died from that cause, especially when there are other possibilities. FFI patients have a genetic disorder that affects every cell in their bodies, and suffer significant damage to parts of their brains. It may be that these factors are more directly responsible for their death than sleep deprivation.

Scientists may ultimately decide that lack of sleep is the proximate cause of death in FFI patients, but we don't know right now.

Thanks again for the perceptive comment.

-- Brian Palmer
(To reply, click here)

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