Syncope

Syncope (“SIN-ko-pea”) is the broad medical term for fainting or passing out. This happens when you have a sudden, temporary drop in the amount of blood that flows to your brain.

There are lots of reasons why you may faint. Most of the time, a harmless, short-term cause makes you unresponsive. But in short, syncope can happen if you have:

• A sudden drop in blood pressure
• A drop in your heart rate
• Changes in the amount of blood reaching certain areas of your body

If you faint, you’ll likely become conscious and alert after a few seconds or minutes. But you may feel confused or tired for a bit. You can recover fully in minutes or hours.

What happens in your body during syncope is typically less serious than other types of loss of consciousness. It doesn’t include things that happen during a seizure, for example.

Syncope is a common condition, especially in people over age 70. But syncopal episodes can happen at any age, whether you have a medical issue or not.

Because fainting spells can be a sign of a more serious condition, it’s important to get treatment right away. Most people can prevent problems with syncope once they get an accurate diagnosis and proper treatment.

Signs and symptoms of fainting

The most common syncope symptoms include:

• Blacking out
• Falling for no reason
• Feeling lightheaded or dizzy
• Feeling drowsy or groggy
• Feeling unsteady or weak when standing
• Seeing spots or having tunnel vision
• Having headaches
• Feeling sweaty or nauseous

Causes of fainting

Syncope, or passing out, happens when you don’t have enough blood flowing to your brain. There are many causes for this, depending on the type of syncope. You may have a medical condition that affects your nervous system or heart. Or you may have a condition that affects blood flow through your body and makes your blood pressure drop when you stand up after lying down.

Types of syncope (fainting)

There are many different types of syncope:

• Reflex syncope (which includes vasovagal and situational syncope) is your body’s reaction to certain things happening to you or around you, like standing for a while or feeling stressed.
• Postural or orthostatic syncope (also called postural hypotension) is a sudden drop in blood pressure from a change in position. It may happen when you stand up.
• Cardiac syncope is a lack of blood flow to your brain because of an issue with your heart or blood vessels. These conditions can include: abnormal heart rhythm (arrhythmia), blood clot, heart valve disease or heart failure.
• Neurologic syncope comes from an issue in your brain that limits blood flow there. It can happen when you have a neurological condition like a seizure, stroke or transient ischemic attack (TIA).
• Postural orthostatic tachycardia syndrome (POTS) is an issue with maintaining blood pressure when you stand. But it also involves a fast heart rate (tachycardia) that happens when you stand.
• Syncope with an unknown cause. An increased risk of a syncopal episode is a side effect of some medications. Be sure to follow up with a provider if you don’t know what made you faint.

What are the triggers of syncope?

Triggers of fainting may include:

• Standing for a long time
• Taking decongestants or certain blood pressure medicines
• Being in a hot environment
• Consuming too much food or caffeine, or too many beverages that contain alcohol
• Having too little salt and fluids in your body
• Changing position, especially standing up quickly
• Having a heart-related issue that affects blood flow
• Having an issue with your brain, nerves or spinal cord

How doctors diagnose syncope

A healthcare provider will do a physical exam and a careful review of your medical history. They’ll ask you detailed questions about your symptoms and syncopal episodes. They’ll ask you if you have any symptoms before you faint, and when and where you faint.

They may measure and record your heart rate and blood pressure while you’re in different positions, including lying down, sitting and standing.

You may then have one or more tests to help find the cause of fainting. These tests check things like:

• The condition of your heart
• How fast your heart beats (heart rate)
• The amount of blood in your body (blood volume)
• Blood flow when your body is in different positions

Tests that are used

Tests to determine causes of syncope include:

• Blood tests to check for anemia or metabolic changes
• Electrocardiogram (EKG) to record your heart’s electrical activity
• Exercise stress test to see how well your heart works under stress
• Ambulatory monitor to record information about your heart’s rate and rhythm for days or weeks
• Echocardiogram to create an image of your heart’s structures
• Tilt table test to record your blood pressure and heart rate while a provider tilts the table you’re on (head-up) to different levels
• Autonomic reflex testing to monitor your blood pressure, blood flow, heart rate, skin temperature and sweating in response to certain stimuli
• Electrophysiology study to get a detailed review of your heart’s electrical activity
• Computed tomography (CT) scan to get images of your heart or brain
• Neurological evaluation to check for issues with your nervous system

What to do if someone faints

If someone faints, follow these steps:

1. Check to make sure they’re breathing.
2. Make sure they lie down or sit with their head between their knees for at least 10 to 15 minutes.
3. Offer the person cold water to drink once they’re conscious.

How do you treat syncope?

Syncope treatments will depend on what makes you faint and the results of your evaluation and testing. The goal of treatment is to keep you from having another syncopal episode.

Treatment options for syncope include:

• Taking medications like beta-blockers or midodrine, or making changes to medications you already take
• Wearing support garments or compression stockings to improve blood circulation
• Making changes like eating small, frequent meals, eating more salt (sodium) or potassium, drinking more fluids and avoiding drinks with caffeine and alcohol
• Elevating the head of your bed (you can use extra pillows or place risers under the legs of the head of the bed)
• Avoiding or changing the “triggers” that cause a syncopal episode, which may include avoiding standing for long periods of time, heat or emotional stressors
• Having biofeedback training to control a fast heartbeat
• Getting a device like a pacemaker or an implantable cardioverter defibrillator for heart problems
• Getting treatment for brain issues, like medicine or surgery
• Standing up slowly

Your healthcare team will develop a treatment plan that’s right for you and talk to you about your treatment options.

When should I see my healthcare provider?

If you faint once and are in good health otherwise, you probably don’t need to talk to a healthcare provider. But fainting may be serious if you felt chest pain, confusion or shortness of breath (dyspnea) when you fainted. This is a case where you should see a provider.

Depending on the cause of fainting, you should have a follow-up appointment with a provider two to four weeks after you get treatment. If a provider finds an issue with your heart’s structure or rhythm, you’ll need more follow-up appointments for that.

Questions to ask your provider include:

• Do you know what caused me to faint?
• How can I prevent the type of syncope I had?
• Do I need additional tests or follow-up appointments?

What can I expect if I have this condition?

With the proper diagnosis and treatment, you can manage fainting. If you’ve had a syncopal episode, you could have another one. Your chances of another fainting spell and how the condition affects you depend on several factors, including:

• The cause
• Your age
• Your sex
• Other medical issues you have

If you have a syncope diagnosis, check your local laws. Some areas require drivers with syncope to contact the license bureau. A provider may recommend you find out the cause and get treatment before driving.

Fainting typically isn’t fatal. Most episodes of syncope aren’t dangerous unless you get hurt when you fall. But syncope episodes can be life-threatening if you have abnormal heart rhythms or a neurologic cause. People with a heart or neurologic issue need to follow up with a provider who can help.

Can fainting be prevented?

Many times, people feel a syncopal episode coming on. They feel lightheaded, nauseous and have heart palpitations (irregular heartbeats that feel like “fluttering” in the chest). You may be able to keep from fainting if you:

• Sit or lie down and put your legs up
• Make a fist with your hands
• Make your arms tense or tight
• Cross your legs or squeeze your thighs against each other

To reduce your risk of fainting, you need to know the cause. Reducing your risk may be as easy as staying hydrated, if that was the issue. If you have a heart condition that caused it, you may need medicine or a device to treat an abnormal heart rhythm.