What is vasovagal syncope?
Vasovagal syncope occurs when you faint because your body overreacts to certain triggers, such as the sight of blood or extreme emotional distress. It may also be called neurocardiogenic syncope.
The vasovagal syncope trigger causes your heart rate and blood pressure to drop suddenly. That leads to reduced blood flow to your brain, causing you to briefly lose consciousness.
Vasovagal syncope is usually harmless and requires no treatment. But it’s possible you may injure yourself during a vasovagal syncope episode. Your doctor may recommend tests to rule out more serious causes of fainting, such as heart disorders.
How common is vasovagal syncope?
Vasovagal syncope is common. It can affect patients at any age. Please discuss with your doctor for further information.
What are the symptoms of vasovagal syncope?
The common symptoms of vasovagal syncope are:
- Pale skin
- Tunnel vision — your field of vision narrows so that you see only what’s in front of you
- Feeling warm
- A cold, clammy sweat
- Blurred vision
During a vasovagal syncope episode, bystanders may notice:
- Jerky, abnormal movements
- A slow, weak pulse
- Dilated pupils
Recovery after a vasovagal episode generally begins in less than a minute. However, if you stand up too soon after fainting — within about 15 to 30 minutes — you’re at risk of fainting again.
There may be some symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.
What causes vasovagal syncope?
There are a number of factors that can increase your chances of fainting:
- Standing still in one position for a period of time
- Stressful or emotional situations
- Hot or warm areas
- Not eating or drinking enough
- Seeing blood or having injections
Please be aware that if you are unwell with diarrhoea or vomiting, an infection or flu, you are more likely to experience these symptoms. It is always important that you drink enough fluids to keep well hydrated, but especially when you are unwell.
What increases my risk for vasovagal syncope?
Please discuss with your doctor for further information.
Diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How is vasovagal syncope diagnosed?
Diagnosing vasovagal syncope often involves ruling out other possible causes of your fainting — particularly heart-related problems. These tests may include:
- This test records the electrical signals your heart produces. It can detect irregular heart rhythms and other cardiac problems. You may need to wear a portable monitor for at least a day or as long as a month.
- This test uses ultrasound imaging to view the heart and look for conditions, such as valve problems, that can cause fainting.
- Exercise stress test. This test studies heart rhythms during exercise. It’s usually conducted while you walk or jog on a treadmill.
- Blood tests. Your doctor may look for conditions, such as anemia, that can cause or contribute to fainting spells.
If no heart problems appear to cause your fainting, your doctor may suggest you undergo a tilt table test. For a tilt table test:
- You lie flat on your back on a table.
- The table changes position, tilting you upward at various angles.
- A technician monitors your heart rhythms and blood pressure to see if the postural changes affect them.
How is vasovagal syncope treated?
In most cases of vasovagal syncope, treatment is unnecessary. Your doctor may help you identify your fainting triggers and discuss ways you might avoid them.
However, if you experience vasovagal syncope often enough to interfere with your quality of life, your doctor may suggest trying one or more of the following remedies.
A drug called fludrocortisone acetate that’s normally used to treat low blood pressure may be helpful in preventing vasovagal syncope. Selective serotonin inhibitors may also be used.
Your doctor may recommend ways to decrease the pooling of blood in your legs. These may include foot exercises, wearing compression stockings or tensing your leg muscles when standing.
You may need to increase salt in your diet if you don’t usually have high blood pressure. Avoid prolonged standing — especially in hot, crowded places — and drink plenty of fluids.
Very rarely, inserting an electrical pacemaker to regulate the heartbeat may help some people with vasovagal syncope who haven’t been helped by other treatments.
Lifestyle changes & home remedies
What are some lifestyle changes or home remedies that can help me manage vasovagal syncope?
The following lifestyles and home remedies might help you cope with vasovagal syncope:
You may not always be able to avoid a vasovagal syncope episode. If you feel like you might faint, lie down and lift your legs.
This allows gravity to keep blood flowing to your brain. If you can’t lie down, sit down and put your head between your knees until you feel better.
If you have any questions, please consult with your doctor to better understand the best solution for you.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Review Date: August 4, 2017 | Last Modified: September 13, 2019
Vasovagal syncope. http://www.mayoclinic.org/diseases-conditions/vasovagal-syncope/home/ovc-20184773. Accessed August 3, 2017.
Vasovagal syncope (common faints). http://www.rbht.nhs.uk/patients/condition/vasovagal-syncope/. Accessed August 3, 2017.
Vasovagal Syncope. https://www.healthcentral.com/encyclopedia/v/vasovagal-syncope. Accessed August 3, 2017.