Vasovagal Syncope

What is vasovagal syncope?

Vasovagal syncope is a type of fainting (a sudden, temporary loss of consciousness). Fainting from vasovagal syncope happens when there’s not enough blood flowing to your brain.

A lot of different conditions can cause fainting. When it’s caused by vasovagal syncope, your heart rate and blood pressure drop quickly due to stress, pain, standing for a long time or other triggers. This drop in heart rate and blood pressure is what reduces blood flow to the brain. 

Vasovagal syncope is the most common cause of fainting. It’s called vasovagal syncope because:

• Vaso refers to the blood vessels.
• Vagal refers to the vagus nerve, which helps control the heartbeat.
• Syncope means loss of consciousness.

It’s important to understand vasovagal syncope, because recognizing symptoms may help prevent injuries from falls if you faint.

Symptoms of vasovagal syncope

Vasovagal syncope symptoms include these warning signs that you may be about to faint:

• Pale or gray skin
• Dizziness
• Lightheadedness
• Nausea or queasiness
• Feeling warm
• Cold sweats
• Blurry vision
• Tunnel vision, where you can only see straight ahead
• Trouble hearing

If you lie down when you notice these warning signs, you may prevent fainting. It may also help to tense the muscles in your arms and legs and to raise your legs. 

During fainting episodes, you may lose consciousness and fall to the ground. These episodes usually last a few seconds to a couple of minutes. 

You may feel tired, lightheaded, queasy or confused after you regain consciousness. If you stand up within 15 to 30 minutes, you may faint again.

Most of the time, these episodes aren’t serious but you could hurt yourself if you fall or if you faint while driving. If you think you hurt yourself, try not to move. Call for help or call 911 if you can.

Most people recover quickly, but it’s important to contact a health care provider after fainting so you can find out what’s causing it. If you’ve already seen a provider and you know you have vasovagal syncope, you don’t need to go back every time you faint.

Causes of vasovagal syncope 

A combination of responses in your body can cause vasovagal syncope. When your body experiences certain triggers, your vagus nerve may react by slowing down your heart rate and widening your blood vessels. This reaction causes more blood to stay in the lower body (legs) so less reaches your brain.

This response can lead to a sudden drop in blood pressure, which can cause fainting. Once you are lying flat as a result of fainting, the blood can reach your  brain again and you wake up.

It’s not always clear why vasovagal syncope happens, but common triggers include:

• Standing in one position for too long, which can cause blood to pool in the legs
• Changing positions quickly from lying down to standing up
• Emotional stress or anxiety
• Severe pain, such as from an injury
• Dehydration, especially after a recent illness like the flu, since lack of fluids can reduce blood volume and lead to fainting
• Heat exposure or exhaustion
• The sight of blood or needles

Less-common triggers are:

• Urinating
• Swallowing
• Coughing
• Straining during a bowel movement

Conditions mistaken for vasovagal syncope

These conditions have symptoms similar to vasovagal syncope, so diagnosis can sometimes be difficult:

• Cardiac arrhythmias: Irregular heartbeats from conditions like AFib, tachycardia, heart valve disorders and other heart problems can cause a decrease in the amount of blood flow to the brain and fainting.
• Seizure disorders: Conditions like epilepsy can cause loss of consciousness.
• Orthostatic hypotension: A sudden drop in blood pressure when you stand up can cause dizziness and fainting.
• Transient ischemic attacks (TIAs): Also called mini-strokes, TIAs can have symptoms similar to vasovagal syncope.

Some conditions (like diabetes, heart disease and Parkinson’s disease) and some medications can make you more likely to faint. For any type of unexplained fainting, you’ll want to see a health care provider for an evaluation. Your provider may refer you to a specialist like a cardiologist or electrophysiologist.

Diagnosis of vasovagal syncope

A thorough evaluation can help determine if vasovagal syncope may be causing your fainting. Your provider may use these diagnostic measures:

• Medical history, asking about your symptoms, triggers and family history.
• Physical exam to help check your overall health and identify any factors that could be causing you to faint.
• Tilt table test, a specialized test that monitors how your body responds to changes in position.
• Echocardiogram, which uses ultrasound to look for heart conditions that may cause fainting.
• Electrocardiogram (EKG), which records your heart's electrical activity and can spot irregularities.
• Exercise stress test, to monitor your heart rhythm while you walk or jog on a treadmill.
• Holter monitor, a portable device you wear to record your heart's rhythm for 24 to 48 hours. It may identify irregularities that may not show up in a standard EKG.
• Blood tests for conditions like anemia.

Vasovagal syncope treatment options

Sometimes, you can treat the condition with these lifestyle changes for syncope: 

• Stay hydrated 
• Talk to your provider about adding more salt to your diet
• Take breaks from standing 
• Learn relaxation techniques to help cope with stress
• Tense your leg muscles periodically or wear compression stockings to help keep blood from pooling in the legs
• Get regular physical activity

If you’re still having symptoms after adjusting your lifestyle, your provider may recommend:

• Medications: Prescribed medications may help regulate blood pressure or heart rate. Alpha-1-adrenergic agonists can raise blood pressure, corticosteroids increase sodium and fluid levels and selective serotonin reuptake inhibitors (SSRIs) can help manage the nervous system.
• Counseling: If anxiety or stress are triggering your fainting episodes, therapy may help.
• Pacemaker: If a slow heart rate (bradycardia) is causing vasovagal syncope, your provider may recommend a pacemaker to maintain your heart rate and prevent fainting episodes. However, it’s rare to need a pacemaker for vasovagal syncope.

Be sure to see your health care provider for follow-up appointments to make sure your treatment plan is working well.

Living with vasovagal syncope

Managing vasovagal syncope involves understanding it and recognizing your triggers. Here are some tips:

• Pay attention to what might cause your fainting episodes and try to avoid those situations.
• Drink plenty of fluids, especially during hot weather or when you don’t feel well.
• If you feel faint, lie down or sit with your head between your legs immediately so you’re less likely to fall and hurt yourself.
• If you faint for more than a few minutes or have other symptoms that concern you, get medical attention right away.
• Connect with support for fainting or community programs for information and encouragement.

Getting care 

Living with vasovagal syncope can be challenging. Seeking help and getting diagnosed and treated can help you minimize fainting episodes. 

At Banner Health, we provide expert care for fainting and vasovagal syncope. Our health care providers use advanced diagnostic tools and are highly trained in treating this condition. We are here to support you every step of the way. 

If you have symptoms of vasovagal syncope or concerns about fainting, don’t hesitate to reach out to Banner Health for expert care and support.