Vasovagal syncope suddenly develops when your body reacts so strongly to a triggerlike seeing blood or being scaredthat youfaint.
Your heart rate and blood pressure plummet, but the heart doesnt stop.
An episode of fainting from vasovagal syncope usually only lasts seconds to minutes.
Verywell / Brooke Pelczynski
Symptoms of Vasovagal Syncope
Fainting from a vasovagal response can be sudden and unexpected.
However, you may have warning signs a few seconds or minutes before a fainting episode.
The signs leading up to fainting are called theprodromeof syncope, or pre-syncope.
The symptoms that come on after you regain consciousness are calledpostdromalsymptoms.
The visual changes are followed by a loss of consciousness.
These symptoms can last anywhere from minutes to hours.
You are at risk of fainting again until these symptoms go away.
Call for help if you are able, and wait for emergency responders to arrive.
You should also call 9-1-1.
Loosen tight clothing around the neck.
Raise the persons feet so they are higher than the heart.
Keep the person lying down for at least 10 to 15 minutes.
What Triggers Vasovagal Syncope?
Vasovagal syncope happens when something triggers thevasovagal reflex, which causes blood vessels to widen (dilate) suddenly.
Dilation of the blood vessels causes a lot of the blood in the body to pool in the legs.
The pooling of blood is accompanied by a slowing heart rate, which leads to adrop in blood pressure.
Theres a strong link between vasovagal syncope andanxiety, and it can have a cyclical effect.
Whos at Risk for Vasovagal Syncope?
The reflex that causes vasovagal syncope can affect anyone and fainting spells are common.
However, some people are more at risk of fainting from vasovagal syncope than others.
If you have heart problems, syncope could be a warning sign of something more serious.
To diagnose vasovagal syncope, your healthcare provider will review your symptoms, medical history, andfamily history.
Youll also be asked about the events leading up to your fainting episode.
Fainting episodes can come at inconvenient, impractical, and unsafe times.
While vasovagal syncope is not life-threatening, the consequences of fainting can be.
Treatment for vasovagal syncope usually includes a combination of strategies like medication and exercise.
If you have recurrent syncope, ask your healthcare provider before starting a fitness plan.
How Can You Prevent Vasovagal Syncope?
If youve had one or two episodes of vasovagal syncope, youve probably learned to spot the warning signs.
You may even be able to prevent an episode by lying down and elevating your legs.
Summary
Vasovagal syncope happens due to a sudden drop in blood pressure and heart rate.
It can be triggered by events like an anxiety attack or a blood draw.
Your provider can run tests to rule out other causes of fainting, some of which can be serious.
Learning your triggers and trying to avoid them is the best way to prevent vasovagal syncope.
Medications and/or certain exercises can also help.
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