Home Health A-Z Vasovagal Syncope: Causes, Symptoms, Diagnosis, Prevention & Treatment

Vasovagal Syncope: Causes, Symptoms, Diagnosis, Prevention & Treatment

Verified By Apollo Doctors July 14, 2022 2543 0
Vasovagal Syncope
Vasovagal Syncope


Vasovagal syncope is a medical condition when a person faints due to a specific trigger. Vasovagal syncope, also known as neurocardiogenic syncope, is the most common cause of fainting. Usually, it is not harmful and not a sign of a more serious condition.

In this situation, your pulse and blood pressure drops suddenly, which reduces the amount of blood flowing into your brain. Hence, you experience brief unconsciousness.

Vasovagal syncope episode is a harmless condition that needs no treatment. However, there are high chances of you hurting yourself during an episode. In this condition, the doctors usually recommend some tests to understand if the reason for fainting is serious, which may include heart problems.


While fainting is the most prominent symptom of vasovagal syncope, here are a few other symptoms that you may observe:

  • Paleness of skin. 
  • Feeling lightheaded.
  • Experiencing tunnel vision in which the vision area narrows down such that you only see whatever is in front of you
  • Nauseated feeling. 
  • Feeling warm or hot.
  • Feeling cold and clammy and sweating.
  • Blurred Vision. 

If you experience a vasovagal syncope episode, people around you can recognize it by the following symptoms:

  • Jerky and abnormal movements. 
  • A slow and weak pulse rate.
  • Dilated pupils.

The recovery process after a vasovagal episode generally begins within a minute. But if you stand up suddenly or too soon after fainting, you are at risk of fainting again.


Vasovagal syncope’s main causative factor is when a part of your nervous system malfunctions. It is the part that handles the heart rate and blood pressure. Hence, when there is a trigger, it produces significant effects. Many nerves connect with the heart and blood vessels. They regulate the blood pressure by controlling whether your blood vessels tighten or widen . Generally, these nerves coordinate their actions so you always get enough blood to your brain. Under some situations, these nerves may give an inappropriate signal, which may cause your blood vessels to dilate. Similarly, your heartbeat might slow down and blood can pool in the legs leading to a drop in blood pressure, and not enough blood may reach the brain. If that occurs, you may lose consciousness, briefly. When you fall or lie down, blood flow to the brain resumes.

The sight of blood is a classic trigger for a vasovagal syncope episode. But there are other common triggers. These are: 

  • Standing for long durations. 
  • Overexposure to heat. 
  • Blood gets drawn from your body.
  • Any fear is related to injury to body parts. 
  • Straining yourself, for example, during a bowel movement. 

When to See a Doctor?

If you experience this condition, it is advisable to consult a doctor so that any  heart problem or a brain disorder is not missed . You must consult with a doctor when you experience fainting for the first time.

Medications can also cause fainting, specifically antidepressants, and drugs that may alter your blood pressure. If you think that is the case, talk to your doctor about getting alternatives, and don’t stop your medicines on your own.

When your doctor observes that your medicines are causing fainting, they will work out a plan to gradually reduce their intake to eliminate the side effects of the medication.

When to Get Immediate Medical Care? 

You need to get the immediate attention of doctors if you or someone you know faints. Also, consult a doctor if you have the following symptoms:

  • Have a head injury when you faint and fall from a height. 
  • You require more time than usual to gain consciousness.
  • You experience trouble breathing.
  • Pain in your chest
  • Having problems in your hearing, vision, or speech. 
  • Lose control over your bladder or your bowels. 
  • If fainting seems like a seizures
  • When you are pregnant. 
  • If you experience confusion on gaining consciousness.


Doctors start the diagnosis of VVS by first reviewing the patient’s medical history and considering the symptoms. They will also examine you physically. Along with a physical examination, they will also take your blood pressure readings while standing, sitting, and lying down.

The doctor will eliminate the possibility of other complex issues by conducting tests. Some of these tests are:

  • Electrocardiogram (ECG) – It will measure the heart’s electrical activity.
  • Echocardiogram – It examines the motion of the heart and blood flow.
  • Exercise stress test – It evaluates the functioning of the heart after exercise.
  • Tilt-table test – In the test, the doctor secures you on a padded table that moves at different angles. It is attached to various monitors that detect and record the heart activity, oxygen level, and blood pressure by moving the table to different angles and positions.

Read About: Normal Oxygen Level in Human Body

Prevention Tips

Vasovagal syncope is not entirely preventable in all cases. But a person can work towards reducing the number of fainting episodes they experience. Below are some recommendations for the prevention of VVS episodes and the related complications.

  • Identify and avoid conditions that trigger fainting episodes
  • Exercise
  • Drink lots of fluids for maintaining your blood volume
  • Consume a healthy diet, which has adequate salt
  • Wear compression stockings
  • Stop medications that can lower your blood pressure
  • Do not suddenly sit or lie down when feeling dizzy


Vasovagal syncope usually does not require treatment. But sometimes, you may need extra time to regain consciousness after an episode. Hence, a bystander should intervene. They can get you to lie on your back and raise your legs in the air, which will restore blood flow to the brain to help you gain consciousness.

Doctors usually advise you to avoid the fainting triggers and take precautions to prevent injury in case of imminent fainting.

Medication is not usually required for VVS. However, in some conditions, the following medicines can help reduce the frequency of VVS episodes.

  • Alpha-1 adrenergic agonists: These drugs assist in raising your blood pressure.
  • Fludrocortisone: It helps maintain your blood pressure by increasing sodium and fluid levels in your body.
  • Selective serotonin reuptake inhibitors (SSRIs): The antidepressant medications will improve your nervous system response.

Frequently Asked Questions (FAQs)

Does the vasovagal syncope episode make you tired?

After an episode of vasovagal syncope, some people feel uncomfortable for a few hours or few days and even longer duration’s. During the post fainting period, you may experience nausea, dizziness, fatigue, and appetite loss. 

How to live with vasovagal syncope?

If you suffer from vasovagal syncope, then to prevent fainting, you need to stay away from hot places and avoid standing for long durations. If you feel nauseous, sweaty, or lightheaded, you need to lie down and raise your legs. If you face frequent vasovagal syncope, you also need to make lifestyle changes like eating more salt and taking more fluids.

Can anxiety cause vasovagal syncope episodes?

Any form of anxiety can cause the symptoms of dizziness, but many people have reported syncope episodes when they have anxiety about a medical process or a needle phobia.

Can vasovagal syncope be cured permanently?

Generally, Vasovagal syncope is not a very harmful condition, but you may injure yourself during a vasovagal syncope episode. With assistance from your doctor and lifestyle changes, it can get kept under control. 

Verified By Apollo Doctors
At Apollo, we believe that easily accessible, reliable health information can make managing health conditions an empowering experience. AskApollo Online Health Library team consists of medical experts who create curated peer-reviewed medical content that is regularly updated and is easy-to-understand.

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