Sudden unexplained nocturnal death syndrome

Ali Karaki MD (

Dr. Karaki of Lebanese American University Medical Center has no relevant financial relationships to disclose.

Hrayr P Attarian MD (

Dr. Attarian, Director of the Northwestern University Sleep Disorders Program, received honorariums from Clearview and GLG for consulting work, honorariums from Pre Med for speaking engagements, and royalties from Flo for authorship.

Antonio Culebras MD, editor. (

Dr. Culebras of SUNY Upstate Medical University at Syracuse received an honorariums from Jazz Pharmaceuticals for a speaking engagements.

Originally released September 9, 1993; last updated November 17, 2020; expires November 17, 2023


In this article, the authors discuss sudden unexplained nocturnal death syndrome. Often fatal, it is a disorder that occurs in young adult Southeast Asian men who are otherwise healthy. This article includes new information on novel mutations associated with the development of critical arrhythmias that could lead to sudden unexplained death syndrome as well as new epidemiological information in Thailand and the correlation of dysfunctional autonomic response in subjects with family history of the condition.

Key points


• Sudden unexpected nocturnal death syndrome is the most serious of sleep disorders as it affects otherwise healthy people, mostly young Asian men.


• There is an etiologic relationship between sudden unexpected nocturnal death syndrome and other conditions that can cause sudden cardiac death.


• Prevention is possible, as in the implantation of a defibrillator in near-miss cases.

Historical note and terminology

The Centers for Disease Control in the United States applied the term “sudden unexplained nocturnal death syndrome” to the syndrome first recognized in 1915 in the Philippines, originally called bangungut ("to arise and moan," the word for "nightmare") in the Tagalog language. In Japan, the syndrome was identified and named pokkuri ("sudden death") in 1959. In Thailand, sudden unexplained nocturnal death syndrome is called laitai ("sleep death"); in Laos it is called non-laitai ("sleep death"), and in Hawaii it is called “dream disease.” Sudden unexplained nocturnal death syndrome has been identified in Southeast Asian male refugees, primarily the Hmong people, settling in the United States since 1975 and was the chief cause of death among these male refugees in the early 1980s, which was the peak time of Southeast Asian immigration to the United States (Nakajima et al 2011).

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