Local doctors warn that fainting among young people for no known reason can lead to sudden death if symptoms go untreated.

There’ve been a number of cases in which people under 40 years of age have suffered from seizures and fainting spells without warning. Without proper diagnosis and treatment, fainting may recur and the patients may not survive.

Prof. Dang Van Phuoc, chair of Ho Chi Minh City Cardiovascular Illness Association, also a leading expert in the field, warns that young people should take this loss of consciousness or perception seriously, no matter how brief it is.

Apart from neurological illnesses, cardiovascular complaints are the most common cause of fainting among young healthy people—even top athletes, Phuoc noted.

Cardiovascular complaints include long QT syndrome (LQTS), a disorder of the heart’s electrical activity. It can cause sudden dangerous arrhythmias (irregular heartbeats) in response to exercise or stress and can result in sudden death. People suffering from LQTS also can have arrhythmias for no known reason.

Phuoc stressed that another common syndrome among Southeast Asians is Brugada Syndrome, a genetic disease characterized by abnormal electrocardiogram findings. Brugada Syndrome is the most common cause of sudden death among young Thai and Laotian men who do not suffer from known cardiac disease.

One of the difficulties is that the irregularity of the heartbeat isn’t always diagnosable and needs advanced testing such as cardio ultrasonograms or Holter electrocardiograms to detect it.

As fainting is usually accompanied by seizures, doctors can misdiagnose it as epilepsy. Those with close relatives who suddenly die in their 40s or earlier are more susceptible to the risk of untimely, sudden death.

With early diagnosis, an irregular heartbeat can be properly treated and sudden deaths among young people can be prevented, Phuoc concluded.