Lethargic sleep is not a rare but poorly studied phenomenon, which is why all the stories about people falling asleep deeply and for a long time seem so frightening.
In the mild form of lethargy, the person looks asleep, but it is impossible to wake him up, in severe cases, the heart rate slows to 2-3 beats per minute, the skin becomes pale and cold, breathing is almost absent, the person seems rather dead.
The fear of being buried alive has existed probably as long as mankind has existed. But only in the 19th century did they begin to make “safe” coffins. They were equipped with a special tube for breathing, which was led to the surface, so the person had something to breathe.
Some models of coffins were equipped with a bell. Priests would come to the graves after the funeral to make sure that the person was really dead. If the smell of putrefaction was detected through the tube, the grave was finally buried.
The poet Petrarch during his serious illness, he periodically lost consciousness until he fell into a lethargic sleep, and woke up when he was already being prepared for burial. It is noted that his condition improved, and he was able to live another 30 years.
The famous writer Nikolai Gogol feared he would be buried alive. As a young man, he suffered from malarial encephalitis, the disease did not go away, and he periodically had fainting spells, after which he would fall soundly asleep. His fear of being buried alive increased with age, and in his later years, he even slept sitting up in order to wake up more quickly if he was accidentally thought to be dead.
When the writer’s grave was opened, his body was lying in an unnatural position with his head turned on its side. The legend that he was lowered into the grave alive still walks. But there is a perfectly trivial explanation. The boards of the coffin rotted unevenly, which caused the writer’s body to take the position in which it was caught at the exhumation.
There are several reasons why lethargy develops. According to one of them, a person who is undergoing serious stress can fall into a lethargic sleep. Another reason is a virus, which was especially widespread in Europe in the early 20th century, when cases of lethargic sleep became more frequent. It has also been observed that lethargy develops in people prone to frequent sore throats after another exacerbation.
There is a theory that the state of lethargic sleep is caused by mutated staphylococci that infiltrate brain tissue and cause changes.
States similar to lethargic sleep can occur in people suffering from encephalitis or narcolepsy, as well as when taking certain drugs. It can also be a precursor to coma, such as head trauma and severe blood loss.
There is no unequivocal answer to what causes lethargic sleep; this question is still waiting to be investigated.