[Sportschosun, Jang Jong-ho] A person may suddenly feel nauseated and break into a cold sweat, followed by blurred vision. Their ears may feel blocked, or they may lose strength throughout their body. In severe cases, they may lose consciousness. These symptoms can commonly occur with vasovagal syncope.
Vasovagal syncope is one of the most common causes of fainting. When the autonomic nervous system overreacts to a particular situation, blood pressure may drop or the heart rate may slow. As a result, blood flow to the brain temporarily decreases, causing a person to lose consciousness. The condition itself is usually not life-threatening, but secondary injuries—such as hitting the head or suffering a fracture in a fall—can be serious.
With guidance from Professor Shin Seung-yong of the Department of Cardiology at the Cardiovascular and Cerebrovascular Hospital, The Catholic University of Korea Seoul St. Mary's Hospital, here is an overview of vasovagal syncope.
◇ Stress, Fatigue and Dehydration Can Make Fainting More Likely
One characteristic of vasovagal syncope is the appearance of prodromal symptoms before a person loses consciousness.
Common symptoms include dizziness, nausea, cold sweats, paleness, a feeling of warmth or suddenly becoming overheated, blurred or narrowed vision, muffled hearing, a racing heart, yawning and general weakness.
The problem is that these symptoms do not appear in exactly the same way in everyone. Some people experience prominent dizziness, while others first notice indigestion-like discomfort or nausea. In atypical cases, a person may only feel vaguely unwell or suddenly lose strength.
Therefore, when prodromal symptoms are not clear, it may be difficult to suspect vasovagal syncope from the outset. By contrast, people who experience it repeatedly often gradually learn to recognize their own distinctive warning signs before fainting.
Fainting can occur more easily when stress, fatigue and dehydration overlap. Vasovagal syncope is often triggered in specific situations, such as standing for a long time, being exposed to a hot environment, experiencing severe pain or fear, or having blood drawn or receiving an injection.
Severe fatigue, insufficient sleep and ongoing psychological stress can also disrupt the balance of the autonomic nervous system. If a person has not eaten properly or consumed enough fluids, dehydration and reduced blood volume may occur together, creating conditions that make fainting more likely. Particular caution is needed after heavy sweating in hot weather or when a person has to stand for a long time without having enough water or food because of a busy schedule.
However, it is not accurate to simply explain that "fainting occurs because the vagus nerve becomes weaker when a person experiences a lot of stress." Vasovagal syncope results from a combination of various triggers and an individual's autonomic nervous system response.
◇ Sit or Lie Down Immediately to Avoid Fainting and Prevent Secondary Injuries
If you notice prodromal symptoms, lower your body position immediately rather than trying to endure them
One of the most important ways to respond to vasovagal syncope is to recognize your own prodromal symptoms.
It is not advisable to remain standing and endure the symptoms while thinking, "I will probably feel better in a little while." Falling unconscious and hitting the floor or nearby structures can cause more serious problems, including injuries to the head or face.
When familiar prodromal symptoms begin, sit in a safe place or, if possible, lie down immediately. If you can lie down, raising your legs may also help maintain blood flow returning to the brain.
If lying down is difficult and you are still fully conscious, physical counter-pressure maneuvers—such as crossing your legs and tensing both legs or clasping your hands and pulling them against each other—may help maintain blood pressure.
In daily life, it is important to drink enough fluids and avoid excessive stress and dehydration. If you know that prolonged standing or hot environments tend to trigger fainting for you, preparing for those situations in advance can also help.
However, not every fainting episode should be attributed to the vagus nerve. Professor Shin Seung-yong emphasized, "Cardiac syncope caused by an arrhythmia or structural heart disease is also possible, and in some cases, a much more serious underlying cause may be present. In particular, fainting during exercise, fainting accompanied by chest pain or severe palpitations, suddenly collapsing without any notable prodromal symptoms, fainting in someone with heart disease, or recurrent fainting or an episode that differs from previous ones requires a thorough evaluation by a medical professional."
Vasovagal syncope is common and generally has a favorable prognosis. Rather than viewing it simply as a disease caused by a weak vagus nerve, it is more accurate to understand it as a physiological phenomenon in which dehydration, external stress and other factors, together with autonomic reflexes, temporarily lower or slow blood pressure and heart rate.
Because it is a physiological response, similar conditions can produce the same reaction, making avoidance of similar situations the most effective form of prevention. Nevertheless, people who repeatedly face unavoidable overwork, stress or dehydration because of their jobs and frequently experience recurring symptoms should remember their own prodromal signs. Professor Shin Seung-yong advised, "Recognizing the signals your body sends at an early stage and sitting or lying down immediately can help you avoid actually fainting and prevent a substantial proportion of secondary injuries, such as falls and trauma, caused by fainting."
Jang Jong-ho, Reporter bellho@sportschosun.com
This article has been translated by GripLabs Mingo AI.
