Fainting Suddenly on Subways and in Restrooms: Why Are People in Their 20s and 30s Collapsing?

〈Anchor〉

"I suddenly couldn't hear or see," and "My legs gave out and I collapsed on the spot." Stories like these are frequently posted on social media and online communities these days. It is said to be commonly experienced by young adults in their 20s and 30s, particularly women.

〈Reporter〉

This condition is called vasovagal syncope.

It reportedly starts with sudden nausea and cold sweats, turning pale, muffled hearing, and darkening vision, followed by a loss of strength in the legs leading to a collapse.

However, this happens much more frequently than people think.

As many as half of all patients visiting emergency rooms for fainting are diagnosed with vasovagal syncope.

It is the most common form of fainting, but what is the reason?

Our bodies have an "automatic control system"—known as the autonomic nervous system—that regulates functions like heart rate and blood pressure without requiring conscious thought.

This autonomic nervous system reacts more than necessary when triggered by specific stimuli, such as sudden severe stress or pain, standing for a long time, coughing, having a bowel movement, feeling too hot, or being in a confined space.

When this autonomic response becomes excessive, the heart rate slows down and blood flow velocity decreases, ultimately causing blood pressure to plummet.

When blood pressure drops, the brain temporarily lacks adequate blood supply, resulting in a loss of consciousness.

After looking through various personal accounts, a common pattern emerged.

First, it occurs predominantly in young women.

In fact, various studies report that vasovagal syncope is 1.5 times more common in women than in men, and particularly prevalent among younger age groups.

[Yoon Ji-eun / Department of Neurology, SoonChunHyang University Bucheon Hospital: Women generally have lower blood pressure and a slightly lower circulating blood volume. In addition, female hormones like estrogen affect blood vessel dilation and autonomic regulation, which is also related. (Also) While it is difficult to say that crash dieting or low body weight itself is a direct cause, dieting and low body weight lead to reduced food intake, lower water intake, and insufficient salt intake, which can cause blood volume and blood pressure to drop sharply, making individuals more vulnerable to fainting. (Why does it occur less frequently with age?) As people get older, the reactivity of the autonomic nervous system, including the vagus nerve, decreases, and the degree to which heart rate and blood vessels react sharply diminishes.]

Next are specific locations, namely subways and restrooms.

[Yoon Ji-eun / Department of Neurology, SoonChunHyang University Bucheon Hospital: Subways are environments where multiple conditions that can trigger vasovagal syncope overlap. Standing for a long time causes blood to pool in the legs due to gravity, and blood pressure can drop further as blood vessels dilate to lower body temperature in a hot environment. Also, when subways are crowded, it can feel stuffy and tense, commuters may feel fatigued during rush hour, and if they haven't eaten, an empty stomach combined with dehydration can create a situation where fainting is more easily triggered.]

Restrooms are similar. First, taking a hot shower causes skin blood vessels to dilate, which lowers blood pressure. When combined with the posture of standing for a long time, it creates a state where fainting easily occurs.

The final common denominator is engaging in "specific actions," such as vomiting.

[Yoon Ji-eun / Department of Neurology, SoonChunHyang University Bucheon Hospital: When vasovagal syncope occurs, not only does blood pressure drop, but other parasympathetic nervous responses, including the vagus nerve, become stronger. This can increase gastrointestinal motility, causing nausea, stomach aches, a sudden urge to defecate, along with cold sweats and paleness. If you feel like you are going to faint, it is important to lower your posture immediately before falling. If possible, lying down right away and raising your legs higher than your heart can help restore blood flow to the brain. If lying down is not possible, sitting or squatting down and crossing your legs while tensing the muscles can also help.]

Fortunately, vasovagal syncope itself can mostly be managed through everyday lifestyle adjustments without special medication.

[Yoon Ji-eun / Department of Neurology, SoonChunHyang University Bucheon Hospital: The most important thing in prevention is avoiding dehydration and situations where blood pressure drops. It is generally best to drink plenty of water, avoid starving for too long or going on extreme diets, and when you sweat a lot, replenishing appropriate salt along with fluids can also be helpful.]

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