"Bangungot" is a word from the Tagalog language meaning "to rise and moan", but that belies the true terror of this word: it refers to a syndrome in which people mysteriously die in their sleep, with no previous indication that there was anything wrong with them. The name comes from the tendency of victims to cry out and thrash in their sleep before expiring.
Before you stay up all night in terror: It only appears to affect people of southeast Asia, including Thai, Hmong, and Filipinos, and then only young males of median age 33.
Medical research is beginning an inquest into this syndrome, but so far everyone's baffled. While the syndrome is well-known among these ethnic groups, it is shrouded in urban legends and old-wives' cures, said to be caused by everything from eating a heavy meal before bedtime to being visited by a vengeful female spirit, with a folk remedy of pinching the big toe of a sleeper as a preventative cure. It's even been culturally compared to the urban legends of UFO abductions in the US, and the old-world concept of a "night terror" or sleep paralysis, so eloquently depicted in Johann Heinrich Fussli's painting The Nightmare, shown above.
Of course, the idea that a scary dream that can actually kill you also is at the root of another pop cultural icon, the Nightmare on Elm Street series with the character of Freddy Kruger being a nocturnal assassin.
However, one possible clue to the syndrome's cause is that this tends to affect only refugees from those countries; people already undergoing a large amount of stress, who might naturally be subject to spontaneous cardiac arrests and related events.