Syncope (fainting)

Find a heart specialist

We understand fainting can be an uncomfortable experience. At Aurora, we take fainting spells seriously. In fact, syncope, another name for fainting, is one of our specialties. Syncope is usually nothing to get worried about, but it can be a sign of a more serious condition. That's why it’s important to get treatment right away after you have a syncopal episode.

Our emergency department doctors use a dedicated hotline to talk with one of our syncope specialists – day or night – to pinpoint the cause of your syncope and make sure you get exactly the right treatment.

Syncope definition

Syncope (pronounced SINK-oh-pee) is the medical term for fainting or temporarily passing out. It’s a common condition, accounting for approximately 1%-3% of all emergency room visits and up to 6% of hospital admissions nationwide each year.

The definition of syncope or a syncopal episode is a temporary drop in blood flow to your brain due to a sudden change in your blood pressure, heart rate, or the amount of blood in certain parts of your body.

A syncopal episode can be triggered by something easily correctable, such as forgetting to eat or drink, or it can be a sign of a more serious heart condition. When syncope is caused by certain triggers, like the sight of blood or intense fear, it's sometimes called vasovagal syncope or reflex syncope.

Syncope signs & symptoms

If you have syncope, the main symptom is occasionally fainting or passing out. Before you faint, you may also experience other symptoms of a syncopal episode. These may include:

  • Blacking out
  • Cold, clammy sweating
  • Falling for no reason
  • Feeling dizzy
  • Heart palpitations or irregularities with your heart rhythm
  • Lightheadedness or feeling as if you might fall
  • Nausea
  • Pale skin
  • Vision changes where everything seems blurred, you see spots, or you have tunnel vision and see only what is directly in front of you
  • Yawning or feeling drowsy for no reason

What causes syncope?

A syncopal episode is often caused by something that’s easily treatable, like dehydration. Sometimes syncope is caused by a life-threatening condition, like a dangerous, irregular heart rhythm.

Common causes of syncope include:

  • Dehydration or low blood sugar from going without food for a long time
  • Intense pain
  • Being under the influence of drugs or alcohol
  • Hard coughing
  • Abrupt change in physical posture, such as standing up too quickly
  • Emotional response to a traumatic – or sometimes even extremely happy – event
  • Cardiovascular conditions such as:
  • Neurological disorders such as:

Types of syncope

There are several different types of syncope. It can be related to underlying cardiac or neurological conditions. Other cases of syncope have no known cause.

Vasovagal syncope (also called neurocardiogenic syncope) causes syncope when you see blood or experience other emotional distress. Your heart rate and blood pressure drop suddenly, leading to reduced blood flow to your brain, which causes you to lose consciousness.

Vasovagal syncope is usually harmless and requires no treatment. It is the most common type of syncope. Nearly half of syncope cases are vasovagal syncope.

If you faint frequently, and it’s not caused by dehydration or a sudden change from lying down to standing or vice versa, you may need to be tested for cardiac syncope. Cardiac syncope is a higher risk in men and those over age 60.

Common causes of cardiac syncope include:

  • Arrhythmia: During episodes of arrhythmia, or an irregular heart rhythm, the heart works inefficiently, and not enough oxygenated blood circulates to the brain
  • Aortic dissection: This is a tear in the aorta, the large artery that carries blood from the heart to the rest of the body. It’s a rare but life-threatening condition
  • Aortic valve disease: This is a narrowing of the valve between the heart and the aorta. The condition can be present from birth or develop in old age

Neurologic syncope is much less common than other types of syncope. It can happen when you have a neurological condition such as a seizure, stroke or transient ischemic attack (TIA), also known as a ministroke. Other less common conditions that lead to neurologic syncope include migraines and normal pressure hydrocephalus.

Postural orthostatic tachycardia syndrome (POTS), also known as postural syncope, is a condition that causes your heart to beat faster when you go from sitting or lying down to standing up. If you have POTS, your body can’t keep your blood pressure steady and stable.

You’re at higher risk of developing POTS after serious infections such as mononucleosis, pregnancy, or head injury. People with autoimmune conditions including Sjogren’s syndrome, lupus, and celiac disease are also more likely to develop POTS.

Most people with POTS are women between 15 and 50 years old. Symptoms can come and go over a period of years. In most cases, adjustments in diet, medications, and physical activity will improve quality of life for people with POTS.

How syncope is diagnosed

Because a serious, underlying medical condition may have caused your syncope, we take extra steps to precisely identify what caused your syncopal episode. At every one of our emergency departments (ED), we follow the same, coordinated procedures to examine you, which means you get the most advanced care no matter your location.

If we determine your syncopal episode is likely a one-time event, we’ll reassure you right away. We’ll talk with you about fainting and the common causes to help you avoid a syncopal episode in the future.

If your syncope is not easily explained, we may order some diagnostic tests to gather more information. Common tests we may order for you include:

  • Tilt-table test, which moves you from lying down to almost standing and monitors your heart’s electrical activity, blood pressure and nervous system reaction
  • Blood-volume determination to measure the amount of blood in your body and the amount of plasma and red blood cells in your blood
  • Hemodynamic testing to measure how well your body carries oxygen through your blood
  • Electrophysiology study, where we use a thin, flexible tube called a catheter to stimulate your heart’s electrical system and record your heart rhythm

Find out more about our heart and vascular testing and diagnosis.

Syncope treatment

While you’re in the ED, day or night, we’ll call our dedicated syncope hotline to talk with one of our electrophysiologists who specialize in syncope to determine your best treatment. And if we suspect that an underlying cardiovascular or nervous system disorder is causing you to faint, we can quickly call in our experts in emergency heart care to treat you.

Depending on what caused your syncope, your treatment plan – personalized for you – may include:

  • Dietary changes such as eating more often, drinking more fluids, consuming more potassium or sodium, or avoiding caffeine or alcohol
  • Practical adjustments like raising the head of your bed while you sleep or wearing compression stockings to improve your blood circulation
  • Care follow-up with one of our syncope or other experts, usually within a few weeks of your visit to the ED
  • Medication to treat an underlying disorder that is causing you to faint

If you have cardiac syncope, we may perform:

Get care

We help you live well. And we’re here for you in person and online.

Find a cardiologistFind a locationGet a second opinionSign in to LiveWell