Syncope is transient fainting due to decreased blood flow to the brain.

All the general information concerning the mechanisms causing unconsciousness, the symptoms and the different types of syncope are presented under the heading: The syncope, a dizzying subject.




Vasovagal syncope is part of the so-called reflex syncope family.

It is by far the most common of all syncope. It is estimated that 1 in 4 people will have at least one episode of vasovagal syncope in their life.

Most of the time, standing for a long period (often in a warm place) or emotional or painful stress triggers this type of syncope.

A common example is the person who loses consciousness during a blood test. The sight of the blood activates the reflex mentioned above, which causes syncope.


The vasovagal pre-syncope is accompanied by so-called vagal symptoms, namely nausea, looking pale, sudden heat wave, tiredness and a great fatigue. This fatigue can continue after the syncope.


Which tests can be requested?

The doctor diagnoses a vasovagal syncope based on the answers to his questions and the physical examination of the patient.

No additional testing is required unless the physician is looking for another cause.

In less conventional cases, the tilting table test can be used to establish the diagnosis. For this test, the patient is attached to a table that tilts at 60-70 degrees, so almost upright, in an attempt to reproduce the symptoms and syncope. This test is rarely used.


What are the risks related to health?

Vasovagal syncope is benign. We do not die of this situation and there are no cardiac complications.

As described above, although 1 in 4 people will have at least one episode of vasovagal syncope in their life, only 1 in 20 people will have more than 5 episodes.


Essentially, as in other types of syncope, there is a risk of trauma associated with falling.

Fortunately, pre-syncope symptoms generally last long enough to allow the person to attempt methods to relieve pressure, such as sitting or lying down and preventing fainting or wounds, in case of a loss of consciousness.


What is the treatment?

Be aware that any condition that lowers the pressure can increase the risk of syncope. This is mostly dehydration and some drugs. So, it is recommended to drink about 2 liters of liquid per day and not to restrict on the salt, unless otherwise advised by the doctor.

The easiest way to prevent fainting or injury is to lie on the floor with your legs in the air. In fact, when lying down, the blood that is in the legs because of gravity circulates again in the whole body, improving the pressure and preventing a loss of consciousness.

However, lying down on the floor is not always possible everywhere. There are some maneuvers to try to prevent a drop in pressure.


A few tricks:

• One method is to cross the legs and contract each of them over each other isometrically, that is to say without moving.


• The other is to squeeze your hands, one in the other, in front of you, and to pull on them equally, as to remain still.

• In addition, it is important to inform the others about the possibility of having syncope. During a pre-syncope, they can help prevent injuries.


These measures generally prevent a good deal of syncope episodes. There is only a small minority of people with vasovagal syncope who require further intervention.

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Syncope, fainting or loss of consciousness is transient fainting due to decreased blood flow towards the brain.

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