Understanding Sudden Unexplained Nocturnal Death Syndrome: The Silent Threat That Claims Lives During Sleep

We often hear news about celebrities who pass away quietly in their sleep, a condition known as "Sudden Unexplained Nocturnal Death Syndrome" (SUNDS), which is especially common among working-age adults in Southeast Asia. What causes this syndrome, and can it be prevented? Tags: ["Sudden unexplained nocturnal death syndrome", "working-age adults", "Southeast Asia", "causes", "prevention"]

What is Sudden Unexplained Nocturnal Death Syndrome?

Sudden unexplained nocturnal death syndrome (SUNDS) refers to death occurring during sleep without an apparent cause. It is known by different names in various regions: in Thailand, it is called "Lai Tai"; in Japan, "Pokkuri Death Syndrome" (PDS); and in the Philippines, "Bangungut."

SUNDS is a hereditary disorder caused by abnormalities in heart cells that lead to irregular electrical activity in the heart. This results in a severe form of ventricular fibrillation—rapid, erratic heartbeats—that can cause sudden loss of consciousness and death within a short time.

Symptoms of SUNDS vary; some individuals may show no signs at all. Most patients die suddenly during sleep without prior warning. However, some may experience early symptoms such as:

• Irregular heartbeats, palpitations, or shortness of breath.
• Seizures or convulsions accompanied by breathing difficulties during sleep.
• Fainting or loss of consciousness while sleeping.
• Loud breathing sounds or gasping as if struggling for air.
• Involuntary urination or defecation.
• Bluish discoloration of the face and lips.

If such symptoms are observed, immediate hospital care is critical. Although there is no cure targeting the root cause of SUNDS, treatment focuses on managing arrhythmias through interventions such as implanting a pacemaker, catheter ablation, or medication, as determined by the physician.

Risk Factors to Avoid

Certain factors can trigger severe arrhythmias in individuals with the genetic predisposition for SUNDS, potentially leading to death. These include:

• High fever.
• Consumption of alcoholic beverages.
• Use of sleeping pills.
• Potassium deficiency.

Can SUNDS Be Prevented?

If you are at risk, it is important to reduce or avoid the triggering factors mentioned earlier. For example, managing high fever with antipyretics and avoiding alcohol. Additionally, implanting a cardiac pacemaker may be recommended.

Moreover, even those without a family history should have a regular annual electrocardiogram (ECG) screening. This helps detect dangerous arrhythmias early, reducing the risk of SUNDS by enabling preventive measures.

SUNDS occurs worldwide but is most common in Asia, especially Southeast Asia—including Thailand, Myanmar, Laos, and the Philippines—primarily affecting working adults aged 30 to 50. It is more frequent in men, with an incidence of about 1 in 1,000 people, compared to 1 in 2,000 elsewhere. In Thailand, it is mainly reported in the northern and northeastern regions, less so in the south.

Research is ongoing to understand why Southeast Asians are at higher risk for SUNDS compared to other ethnic groups.

Sources: Faculty of Medicine, Chulalongkorn University; Vimut Hospital; Faculty of Medicine, Ramathibodi Hospital.