“Don’t fall asleep…”
This is a line that kept me up at night, made me afraid to sleep when I was younger, and a line from Nancy Thompson, the protagonist of Wes Craven’s 1984 film A Nightmare On Elm Street. Most of you may think of this as purely an imaginary situation, where falling asleep results in nightmares and eventually death, but what most people don’t realize is that this was a reality for many people. This was due to a mysterious phenomenon now known as the Sudden Unexplained Nocturnal Death Syndrome (SUNDS).
Widely known as the Nightmare Death or the Nocturnal Death, it is also referred to as Lai Tai in Thailand, Pokkuri Death Syndrome in Japan, Dream Disease in Hawaii, Sudden Manhood Death Syndrome in Mainland China, Sudden Adult Death Syndrome in England and Bangungut in the Philippines.
With the first case being reported in 1917 in the Philippines, it created a little folk tale, referred to as the Bangungut. The Bangungut is depicted as a mythological creature (also known as the Batibat or the Bangungot) and often described as large and almost hag-like by many. The creature is said to have sat on its victim’s face or chest, immobilizing them and sometimes causing death. This folk story is also tied to sleep paralysis in some cases. The other countries that refer to this phenomenon later described the cases as a syndrome or illness.
It has been 108 years since the first description of SUNDS. Since then, two major active periods of studies on SUNDS have accumulated vast information for further understanding of the pathogenesis. Both studies are from the Center of Disease Control in the U.S.
The leading factors behind SUNDS deaths are believed to be a mix of cardiac anomalies in the patient and night terrors. According to a medical article by Ronald B. Melles and Barrett Katz (1988), “Night terrors are a sleep disorder characterized by vocalization, motor activity, a non-arousable state and severe autonomic discharge. The proposed recognition of both night terrors and cardiac anomalies in patients offers a pathophysiologic mechanism for their sudden death.”
Reported victims of this syndrome include males from Southeast Asia, roughly within the ages of 20-30, sometimes in their 40s or 50s. A number of them were Hmong Refugees — these people were forced to flee from their homes in Southeast Asia and Laos after the Vietnam War and Laotian War because they had previously been allies of the U.S. Later, they resettled in various countries such as Australia, France, Canada and the U.S, with the majority of this population now residing in the latter.
Although cases of SUNDS have been slowly growing more widespread ever since the first report, few paid attention. However, it eventually grasped the attention of classic horror movie director Wes Craven, who is known for his movies such as A Nightmare on Elm Street, The Last House on The Left, The Hills Have Eyes and the SCREAM franchise.
In an interview with fellow movie director, Mick Garris, Craven said the idea for A Nightmare on Elm Street first came to him when he was watching television late one night, and a story came regarding a young man who died after having what could only be described as “horrible nightmares.” The case led to a series of different articles regarding similar cases, one about a boy that claimed that there was a man in his dreams trying to kill him. The boy’s father, a doctor, constantly provided the boy with sleeping pills to hopefully help his child sleep. One morning, however, the police found the boy dead. They also found all of the sleeping pills that the boy’s father had previously given him underneath the boy’s bed. He never took a single one.
Although there have not been any recently reported cases of SUNDS, it seems that it can only take heart issues and a nightmare to make a person become a part of the statistic.

