What makes not getting enough sleep deadly

How long does a person survive without sleep?

USA, 1964. 17-year-old Randy Gardner is in a bad mood, has hallucinations. His physical and cognitive performance is severely restricted. No wonder: the young man has been awake for almost 264 hours without a break - that's around eleven days and nights. Then it happens after all: his eyes close, he nods off.

The experiment, which took place under medical supervision at the time, is still an official guard record according to the Guinness Book of Records. In 2007 a Briton managed to stay awake two hours longer than Gardner, but by that time the category in the Book of Records had long since been abolished due to health concerns.

Pay into a sleep account

After all, research has learned a lot from such experiments. We know, for example, that the organism only makes up for lost sleep in very small quantities. Record holder Gardner showed that after eleven days without sleep, he only needed a single 15-hour night of relaxation. After that, all deficits were made up again and his sleep duration was shortened to seven to eight hours per night.

How can this knowledge be applied to everyday life? "We have a sleep account into which we pay," explains Gerhard Klösch, sleep expert at the University Clinic for Neurology at Med-Uni Vienna. "It is not tragic if, for example, someone sleeps fewer hours on one or two nights within a week, provided that the total weekly sleep time is roughly the same." If, on the other hand, too little is paid into the sleep account over the long term, a deficit naturally arises.

Sleep regenerates the body

Science agrees that sleep is important for numerous regeneration processes in the body. Among other things for digestion, the immune system and the ability to learn. "There is no expression of life that is not directly or indirectly influenced by the sleep process," says Klösch. On the other hand, there is no generally valid definition of the importance or function of sleep that is accepted by all experts.

If the nocturnal recovery phase affects us so much, what happens when we no longer sleep? Can insomnia even lead to death? The good news for all owls: "You can't die of insomnia," says Klösch. Randy Gardner's experiment has shown that at some point your own body forces you to indulge in sleep. "In medicine we say: Sleep is imperative," said Klösch.

Sleep pressure until falling asleep

The explanation for this: If you don't sleep for a long time, sleep pressure builds up continuously. This manifests itself in features that everyone knows: the eyelids almost close, thinking slows down, you yawn, get cold hands and feet or a tunnel-like look. The longer we are awake, the higher this sleep pressure becomes - and at some point the body gets what it needs.

However: the tendency to fall asleep fluctuates, it comes every 90 to 120 minutes. In each case, it would be a good time to go to bed and actually fall asleep. "Sleep gates open and close again. That is why it makes no sense to stay in bed if you have trouble falling asleep. Better to get up again and try again an hour and a half later," advises Klösch.

Fatal insomnia

Incidentally, it is not entirely correct that insomnia cannot lead to death, adds the doctor. There is only one exception: the extremely rare neurodegenerative disease "lethal familial insomnia". "In people with this genetic defect, the brain begins to regress in middle age. Among other things, those centers that are important for sleep-wake regulation are also affected," explains the sleep researcher. The result is severe sleep disorders, in the last few months of life those affected can no longer sleep at all and suffer multiple organ failure. (Maria Kapeller, June 25, 2018)