Vasovagal syncope is a sudden, temporary loss of consciousness caused by a drop in blood pressure and heart rate triggered by stimulation of the vagus nerve. It can also cause symptoms such as paleness, excessive sweating, nausea, and vomiting.
The exact causes of vasovagal syncope, also known as vasovagal syndrome, reflex syncope, neurocardiogenic syncope, or common fainting, are not fully understood. However, it is more common in younger people.
Treatment usually involves strategies to prevent fainting episodes, such as avoiding excessive stress, staying hydrated, using medications when necessary, and in more severe cases, implanting a pacemaker.
Main symptoms
The main symptoms of vasovagal syncope include:
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Sudden, temporary loss of consciousness
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Excessive sweating
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Paleness
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Sensation of heat, weakness, or lightheadedness
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Slow heart rate
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Nausea and vomiting
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Vision changes
Loss of consciousness usually occurs after early warning signs like nausea, dizziness, or vision disturbances. When fainting happens, the person typically regains consciousness on their own within about 30 seconds.
In some cases, vasovagal syncope may also cause brief muscle jerks or involuntary urination while unconscious. These symptoms can sometimes be mistaken for an epileptic seizure.
Is vasovagal syncope harmful?
Vasovagal syncope is generally not considered a serious condition.
Still, it can lead to falls, injuries, and in some cases, life-threatening situations depending on what the person is doing at the time of fainting. For instance, an episode while driving may result in a car accident, or a fall could cause a head injury.
How a diagnosis is confirmed
Diagnosis of vasovagal syncope is usually made by a cardiologist or primary care physician based on the person’s symptoms and medical history. To help confirm the condition, the doctor may recommend tests such as:
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Electrocardiogram (ECG)
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Holter monitoring
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Blood tests
These exams help evaluate heart function and rule out other possible causes.
If symptoms are not typical of vasovagal syncope, a tilt table test may also be ordered to monitor blood pressure, heart rate, and symptoms during changes in body position.
Possible causes
Vasovagal syncope occurs when a reflex triggers stimulation of the vagus nerve, leading to a drop in blood pressure and heart rate that briefly reduces blood flow to the brain.
The exact trigger is not always known, but common situations that may cause vasovagal syncope include:
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Anxiety
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Extreme emotional stress
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Fear
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Pain
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Sudden temperature changes
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Standing for long periods
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Physical exertion
It is one of the most common causes of fainting, especially in people under 40 years old.
However, fainting can also result from other conditions, such as arrhythmias or epilepsy.
Can an episode of vasovagal syncope cause death?
In most cases, vasovagal syncope is harmless and does not cause death. Consciousness typically returns quickly after a fainting episode.
In rare situations, vasovagal syncope may be linked to underlying brain or heart conditions, which can increase the risk of sudden death. However, this is uncommon.
Treatment options
Treatment focuses on preventing fainting episodes by avoiding situations that commonly trigger them, such as:
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Standing for long periods
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Getting up too quickly
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Staying in very hot environments
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Experiencing excessive stress
It is also important to drink enough fluids to stay hydrated. If warning signs of an episode occur, lying down with legs elevated can help restore circulation and reduce the risk of falls or injuries.