Apparently, the human brain is adapted to episodic periods of sleep deprivation. But the fact that we are able to survive one or more sleepless nights does not mean that sleep can be constantly neglected without harm to health.
Sleep is essential for life, but what happens when we don’t get enough of it? Can lack of sleep actually kill us?
At the age of seventeen, Randy Gardner set a world record – 264 hours without sleep. 17-year-old Gardner stayed awake for 11 days and 24 minutes in the company of Stanford University somnologist William Dement, who closely monitored the physiological parameters of the sleepless experimenter, including took an electroencephalogram.
Now Gardner is an elderly man, and he is in good health, which, however, does not mean that lack of sleep is harmless to the body.
On the fourth day without sleep, Gardner began to have problems with coordination and sensory organs, even his olfactory perception was distorted. On the fifth day hallucinations began; the brain went into a very strange state, reminiscent of sleep.
An analysis of the electromagnetic activity of the brain showed that by this time Gardner was no longer completely awake (although he was not lying with his eyes closed); individual parts of the brain went into rest mode and became active again.
After completing his record, Gardner slept for 14 hours and 46 minutes, awoke naturally around 8:40 p.m., and stayed awake until about 7:30 p.m. the next day, when he slept an additional ten and a half hours.
However, after Gardner slept off, Professor Dement did not find any deviations from the mental and physiological norm.
Doctors agree that chronic insufficient sleep can have serious health consequences, such as increased risk of heart disease, diabetes, cancer, obesity, depression and other conditions. However, there is no clear evidence that a lack of sleep can directly cause death in humans, except in very rare cases.
One such case is fatal familial insomnia (FFI), a genetic disorder that affects the brain and prevents people from sleeping at all. FFI leads to progressive deterioration of mental and physical functions, and eventually death. Patients typically survive for an average of 18 months after diagnosis. FFI is extremely rare, affecting only about 40 families worldwide.
Another case is total sleep deprivation, which means staying awake for prolonged periods of time without any sleep. This can happen voluntarily, as in some religious or political practices, or involuntarily, as in some forms of torture or extreme stress.
Total sleep deprivation can have severe effects on the brain and body, such as impaired cognition, mood changes, hallucinations, paranoia, tremors, weakened immune system and organ failure.
However, it is difficult to determine whether these effects are directly caused by lack of sleep or by other factors, such as malnutrition, dehydration, infection or psychological trauma. Moreover, it is ethically impossible to conduct controlled experiments on humans to test the lethal effects of total sleep deprivation.
Therefore, most of the evidence comes from animal studies, which have shown that total sleep deprivation can indeed lead to death in some species.
For example, a famous study in 1989 showed that rats deprived of sleep for two to four weeks died from multiple organ failure. Another study in 2020 showed that fruit flies deprived of sleep for 10 days died from oxidative stress in the gut.
However, these studies cannot be directly applied to humans, as different animals have different sleep needs and responses to sleep loss. Furthermore, some animals can survive without sleep under certain circumstances.
For example, some birds and marine mammals can sleep with one half of their brain at a time, while migrating or hunting. Some insects and fish can enter a state of torpor or suspended animation when deprived of sleep.
So, everyone knows that a sleepy driver is dangerous for himself and those around him – but here are the specific numbers: a person who has slept four or five hours instead of the prescribed seven or eight is four times more likely to have an accident.
But even if you don’t drive, lack of sleep is devastating to the body: In addition, in the long term, lack of sleep is fraught with an increased risk of obesity, type 2 diabetes, stroke, heart attack and depression, scientists say.
In conclusion, lack of sleep can have serious negative effects on health and well-being, but it is unlikely to kill us directly, unless we have a rare genetic disorder or are subjected to extreme conditions.
However, this does not mean that we should neglect our sleep needs, as they are vital for our optimal functioning and quality of life.