Tragic Death Dreams of the Hmong People by EM Hilker

He wouldn’t sleep. It didn’t matter what they tried – quiet music, meditation, sedatives, pleading. He simply refused to sleep. His parents understood, of course – they’d been through so much death and struggle and fear and hope. So much danger. And he was just a boy. If they, with their adult brains that could reason things out and had so many more years to process the good and the bad of the world, if they were having nightmares of the horrors that they’d so recently escaped, what must their son be going through? He was still so small. He was still learning about the world. 

But he still needed sleep. He was making himself sick. 

Something was after him, he’d said, whimpered, sometimes nearly screamed, over and over again. It was coming for him, and if he slept he would die. They didn’t believe him, of course – they understood, and if they were being honest they didn’t really want to sleep anymore either – and so they pleaded and cajoled, and after what felt to them to be ages but was probably days, finally he slept, fighting it until his heavy eyelids drooped and his head sunk into his pillow. Fighting it and fighting it until he finally slumped into a soft warm heap of slumbering child, his small serious face smoothing into the angelic repose of sleep. At last. 

And so, they covered him gently, held back tears of relief, and made their way groggily to their own bedroom.  Their escape from Cambodia had been harrowing for all of them, only to find themselves in a strange new place where they struggled with the language, the climate, their trauma that they hadn’t truly had time to process yet. The whole family needed sleep.

Too soon, the boy’s parents were snatched out of sleep, wrenched back to the waking world by the sound of terrified screaming, and without even really comprehending the situation they stumbled across to the boy’s room, obeying the primal parental need to tend to the distress of their vulnerable child. As they stumbled through the door into the darkness, their jumbled thoughts imagining another nightmare, they reached the abruptly silent boy, reaching out to him almost as one to soothe, to comfort, to ease his terror. To take their beloved son in their arms and let him know he was here, he was with them now. He was safe.

It took only a moment to realize why he didn’t respond to their touch, the keening wail and horror building up in their throats even before they had consciously formed the thought: their son was dead.

The Hmong people of Southeast Asia have had a tumultuous history, to put it lightly. They were once a nomadic tribe in China who lived on the edges of society, in the remote, wild areas of the country. They were primarily agrarian when they had the opportunity to settle, and they kept their history and culture orally until missionaries insisted on creating a written form in the 1950s. Described as an ethnicity rather than a nation – for they are, in their own words, a people without a land – they fled China due to persecution in the 1800s, settling mostly in Laos and Vietnam. During the Vietnam War (1955 – 1975) –  a war which was officially fought between the Northern Vietnamese and Southern Vietnamese, but which came to involve a large number of other nations backing one side of the conflict or the other, as well as nations that had gotten drawn into the war due to proximity –  the American CIA recruited the Laotian Hmong to fight against the North Vietnamese. As the war progressed, Laos became communist, and the Hmong again found themselves persecuted in Laos and Cambodia as well as in Vietnam, and many fled to America to hopefully, finally, live out their lives with their families, in safety.

And what a terrible blow it was, then, when healthy Hmong men who had survived the atrocities and settled in America began to die in their sleep in startling numbers in the 1970s. 

The sleep deaths came as a surprise in virtually each case – with only one known exception, the victims were all male, healthy,  and mostly in their 30s. On average the victims had only been in America for a year and a half, and they weren’t particularly close geographically. The Hmong had settled . The man generally agreed to be the first victim of the rash of sleep deaths in the Hmong population was Ly Houa, a medic living in California, who had been described as both healthy and health-conscious. As more and more victims of this strange death began to pile up – many of whom had complained of recurrent nightmares – authorities became alarmed. Lacking a proper set of facts to properly categorize what was striking the Hmong refugees, a generic name was initially applied: Asian Death Syndrome. This was soon reclassified to be a little more specific to the circumstances: “Sudden Unexpected Nocturnal Death Syndrome” (SUNDS), but the mechanism of action was poorly understood. The dead individuals seem to have died of a cardiac issue, perhaps, but beyond that nothing was clear. Authorities only vaguely understood what was happening, but had no sense of how to stop it.

While this was a mystery to North American authorities, this was a known occurrence in other Asian countries. There wasn’t a known cause or method of prevention, but the outcome of this mysterious ailment was very well known. The Japanese called it “sudden unexplained death at night” (pokkuri). It was known as “moaning and dying in sleep” (bangungut) in the Philippines. “Died during sleep,” or lai-tai, in Thailand. It hadn’t struck anywhere in such numbers over such a short period of time as it did the Hmong in 1970s and 1980s America. Something was at work here, and no one was sure what it was.

One of the reasons this mystery has lingered so long in our collective North American memory is that the rash of deaths, particularly those in California, inspired Wes Craven’s Nightmare on Elm Street series. The physical figure of Freddy Kreuger himself was based on a man who had  frightened the young filmmaker in his childhood, stopping on his way past and staring fixated through the house window where the boy sat playing. The very concept itself, however – death hunting you in sleep, the one thing you can never escape – is directly taken from the tragic deaths that struck the Hmong. Craven has stated in interviews that he was following the stories in the LA Times, recalling specifically the story of one young man who had fled the Cambodian genocide with his parents and settled in America. He began to have nightmares, and refused to sleep for fear that something was waiting in his dreams that would kill him. His parents tried sedatives, pleading, anything to make the boy sleep, but he refused. Finally, because sleep is truly inescapable, he fell asleep on his own, unable to resist any longer. His parents were woken from sleep by their son’s screams. When they reached his room, he was already dead. When the room was investigated after his death, they found sleeping pills under his pillow where he had hidden them instead of taking them, and a coffee pot hidden in his bedroom closet. This was hugely influential on the terror lurking in the Elm Street franchise. 

The thing that gets lost in that story, of course, is the more than 100 Hmong-Americans who came to live a better life and simply died; the pain of the parents of the boy who was afraid to sleep and, when he finally did, died screaming in the night; the families who found went to wake up their brother or father or son, only to find their bodies, unmarked, dead in their beds. This was not merely a spooky anecdote that inspired a beloved 1980s horror franchise – this was the story of a tragedy that for some time must have seemed unstoppable.

Doctors and scientists, when faced with this tragedy, wasted no time in trying to identify and solve the problem. One suggestion that had traction for a while was that this was a delayed reaction from exposure to nerve gas. These men had fought and narrowly survived in a war zone. Dr. Larry V. Lewman disputed this in the LA Times, noting that there’s no pre-existing evidence of any nerve gas behaving in this manner, and that there’s no reason in particular why it would strike only at night, in sleep, nor for that matter why it would strike only men. The Hmong women were certainly exposed as well, and with one exception were unaffected by the sleep death.

Others have chalked it up to more mundane causes: acute hemorrhagic pancreatitis might have played a role, the triggering inflammation generated by alcohol or starchy foods consumed near bedtime, or perhaps simply the stress of moving and culture shock taking a toll on the refugees. None of those explain the numbers of dead, which hadn’t been noted in any other group, though it was generally agreed that those might all be sufficient to cause sleep death in an individual.

The Hmong themselves believed that the deaths had a supernatural cause. In the folklore of the Hmong, there exists a sinister spirit who preys on those who don’t revere their ancestors and the spirits of their home, coming to them in the night as a vindictive woman who traps and crushes them, and they never awake. The spirit is called variously Dab Tsog, Dab Tsong, or Tsog Tsuam, and is fearsome enough that some men (for men are primarily responsible for religious duties) were said to sleep dressed as a woman in the hopes that the spirit wouldn’t recognize them and might therefore pass them by. This spirit has been compared to the stories of the Night Hag, a malicious spirit who is connected to sleep paralysis events in the Canadian east, but the target here is much, much more specific and specifically punitive. 

It was fairly early on that medical professionals realized that this might be a cardiac problem. The prevailing theory behind SUNDS was that the nightmares were coincidental: the heart naturally slows in sleep. It was believed that a heart arrhythmia – a disorder where the body doesn’t properly deliver the electrical signal that causes the heart to contract, or beat – was striking in sleep, causing the victim’s heart to skip a beat, prompting a spasm which then stops the heart. In the 1980s, brothers and cardiologists Pedro and Joseph Brugada identified the cause as an inherited syndrome, called Brugada syndrome for its founders. It was initially a diagnosis to describe an issue occurring in Europeans, but an article in Human Molecular Genetics in 2001 demonstrates quite clearly that the mutation required for Brugada Syndrome is the same as that of the victims of SUNDS, and the two terms were in fact describing the same condition. SUNDS/Brugada Syndrome is now preventable; it shows on ECG scans, which measure the heart’s electrical activity, and those in danger can now be implanted with a type of pacemaker called an “implantable cardioverter-defibrillator” or ICD, which will restart the heart via electrical stimulation, should it stop during sleep. 

This explanation, while certainly scientifically correct, also feels unsatisfactory, or perhaps incomplete. It’s since been shown that Brugada Syndrome is particularly prevalent in those of Asian descent, and is 8 – 10 times more common in men than in women. It covers the facts. But why so many people from one specific group, and why in such a short period of time?

Dr. Shelley Adler, a professor of medicine at the University of California, believes the answer may lie in the connection between the mind and the body. She grants that the physical mechanism at play in these deaths is Brugada syndrome, but alleges that the fears of retribution from Dab Tsog for the rituals they were unable to complete far from their homes, and the legitimacy of their beliefs, activated the nocebo effect, complicated by their heart arrhythmia, and that was the thing that ultimately killed them. This ties into the nocebo effect – the inverse to the placebo effect, where rather than the power of the mind to create healing from inactive substances or the power of suggestion, the effect is to suffer harm from the same. In a sense, then, if Dr. Adler is correct, Dab Tsog did kill the men. Or, their belief in her did. 

The mind is a strange thing. Our bodies can do little without it: it makes our hearts beat and our lungs operate. It makes our muscles contract and release. It lets us dream. In turn, our body gives it the oxygen and chemicals required to think and dream and keep the body running. We still, after hundreds of years of learning and experimenting and hypothesizing, don’t really understand how it works. Can you will yourself dead, or will yourself to not die? Can a parent really lift a car or a piano off their child pinned underneath, or a man in a darkened theater bend a spoon with his mind? The placebo and nocebo effects are acknowledged in medicine, and placebo effect is controlled for in scientific studies, but there’s so much that’s simply unknown still.  Perhaps, as neuroscience continues to advance, we’ll one day understand the mystery behind the number of Hmong killed tragically in such a short time.


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Obsessed with all things dark and weird from a young age, E. Madelyne Hilker has used every opportunity to steep herself in mysterious lore, and is working on her first novel Hallow Earth. She works as a new media producer by day and crochets like a madwoman by night. Maddy lives in small town Ontario, Canada with her family and a large collection of houseplants.