Fainting in Children

Overview

When children faint, they quickly and briefly lose consciousness. About 1 in 7 children faint at some time during their childhood or teen years. Children often outgrow fainting.

Fainting has many causes, most of which aren’t serious. Even a healthy child can faint.

Fainting can be triggered when a child:

  • Doesn’t drink enough water and other fluids (dehydration). 
  • Stands for too long or stands up too fast.
  • Has strong emotional upsets.

Your child may feel light-headed or dizzy before fainting. Most children wake up within seconds after fainting and recover in 1 to 2 minutes. 

Although it’s usually harmless, fainting can be frightening for your child and for you. This is especially true if they faint often. We can help find out why your child is fainting. Together we’ll talk about how to prevent or treat future episodes.

Causes

Fainting occurs when normal blood flow to your child's brain is interrupted. The brain receives less oxygen than it needs.

The most common causes of fainting in children aren’t dangerous. But some children may have an abnormal heartbeat or other serious causes. We recommend seeing your child’s doctor after they faint for the first time.

The 2 main types of fainting (syncope) are:

  • Noncardiac syncope. This is more common and rarely dangerous.
  • Cardiac (heart-related) syncope. This can be a sign that a child has structural or electrical heart problems. 

Seizures are sometimes confused with syncope. Both happen suddenly and cause loss of consciousness. Seizures are caused by abnormal electrical activity in the brain, not by reduced blood flow. Some types of seizures are serious medical disorders that need treatment.

Unlike fainting, a child with a seizure disorder doesn’t feel light-headed or have blurry vision before they pass out. Also, loss of consciousness lasts longer with seizures than with fainting.

Types

Noncardiac syncope

Most fainting in children isn’t related to heart problems and isn’t dangerous. The most common type is called vasovagal syncope (neurocardiogenic syncope).

In vasovagal syncope, your child's body:

  • Reacts to a triggering event by slowing the heart rate and widening (dilating) the blood vessels. 
  • Reduces the heart's ability to pump blood to the brain.

Fainting can be triggered when children feel sudden fear, anger, or frustration. Some young children hold their breath for a minute or less (breath-holding spells) in response to these emotions, causing them to faint. 

Other triggers include: 

  • Being dehydrated or overheated
  • Standing for too long or standing up too fast 
  • Having sudden pain or injury 
  • Seeing blood 
  • Having emotional or physical stress, such as crowding
  • Being sick
  • Taking specific medications
Cardiac syncope

Cardiac syncope occurs when a heart problem affects blood flow to the brain. It’s very rare in children. Heart conditions that can cause fainting include:

  • Congenital heart defect (present from birth)
  • Electrical heart abnormalities caused by inherited (genetic) factors

Your child should be checked for a heart condition if they faint during exercise, or have these symptoms just before fainting:

  • Chest pain
  • Heart palpitations

Symptoms

Your child can have symptoms before and after they faint. 

Before fainting

Thirty to 60 seconds before fainting, your child may feel uncomfortable and need to sit or lie down. Next, specific warning signs can occur:

  • Dizziness or light-headedness 
  • Weakness 
  • Forceful heartbeat 
  • Nausea 
  • Blurred or tunnel vision (seeing only what’s directly in front of them) 
  • Changes in hearing 

A child may also look pale, feel warm or sweaty, or breathe rapidly (hyperventilate). The time between symptoms and fainting varies.

After waking up

After your child wakes up, they may continue to feel dizzy, confused, or tired. Keep them lying down for at least 10 minutes. Getting up too quickly can cause another fainting spell.

Diagnosis

Whether your child has fainted once or often, we need to find the cause. This helps us prevent or treat future episodes.

We’ll ask about your child’s medical and family history. Tell us if family members have:

  • Congenital heart disease (present since birth)
  • Cardiomyopathies (heart muscle disease that can be genetic)
  • Electrical heart problems
  • Seizures 
  • Fainting during childhood 

If you or someone you know was there when your child fainted, we’ll ask what happened before and afterward. Let us know:

  • What your child was doing, especially if exercising or eating.
  • What their surroundings were like.
  • Whether other symptoms occurred.

It’s also important to tell us:

  • Whether your child was dehydrated or ill.
  • How long your child was unconscious.
  • Whether your child takes medications, and if so, what they take.

We’ll give your child a physical, including:

  • Taking their blood pressure and heart rate.
  • Checking their heart rhythms by listening with a stethoscope.

We can often determine the cause of fainting based on this information. If needed, we’ll use one or more tests.

Tests

We may use one or more of these tests to find the cause of your child’s fainting. 

Blood tests

This checks whether a low red blood cell count (anemia) is causing fainting. 

Electrocardiogram (ECG/EKG)

This test tracks the heart’s electrical activity. We check for conditions that cause irregular heartbeat. We use it for children who faint frequently or faint during exercise. 

Echocardiogram

This ultrasound test shows the heart’s size and structure. We can see your child’s heart valves and pumping chambers moving, and the blood flowing through the heart. 

Holter monitor (continuous monitor) testing

A Holter monitor can be used for children who faint often. This method records your child's heartbeat over 24 to 48 hours. Electrodes on your child’s chest are connected to a monitor that your child carries. We ask you or your child to write down activities and any symptoms that occur.

Event monitor

An event monitor records the heartbeat only when symptoms occur. We may use it instead of a Holter monitor if your child faints less than once a day. 

Exercise stress test

This is done while your child exercises on a treadmill or stationary bike. We take EKG readings and monitor blood pressure. Generally, we test children age 10 and older. 

Cardiac catheterization

This procedure produces clear images of your child’s heart and heart’s blood flow. 

We will: 

  • Guide a thin, flexible tube (catheter) through a blood vessel in the groin or arm and to the heart. The catheter releases a contrast dye to create detailed X-ray images. 
  • Find the exact area that’s triggering their irregular heart rhythm (arrhythmia). 
Electroencephalogram (EEG)

This detects brain electrical activity problems so we can learn whether your child has a seizure disorder. We attach small electrodes to your child’s scalp to measure electrical signals moving through the brain.

Treatment

Make an appointment with your child's doctor after your child faints for the first time. We recommend treatment based on the cause of your child’s fainting.

If your child has: 

  • Noncardiac syncope, we can help your child learn to use prevention methods.
  • Cardiac syncope, we can treat the heart condition that’s causing fainting. 

Prevention

For noncardiac syncope, we may recommend these guidelines.

Manage fainting triggers

For the most common type (vasovagal syncope) learn your child's fainting triggers and plan to avoid them. For example, if the trigger is:

  • Overheating, you can limit their time outdoors in the hottest part of the day.
  • Experiencing frustration that causes breath-holding spells, you can talk with your doctor about helping your child manage their emotions.
Increase fluid and salt intake

This raises the total blood volume and blood pressure. Give your child water, juices, milk, or other noncaffeinated drinks.

Teens should drink 2 to 3 liters of fluid each day. All children should drink fluids before and during exercise and sports. 

Act at the first warning signs of fainting

Teach your child to:

  • Stop what they’re doing.
  • Lie down or sit with their head lowered between the knees.
  • Stay there until they stop feeling dizzy or light-headed.
  • Stand up slowly.

This prevents fainting by increasing brain blood flow.

Use simple exercises

This raises blood pressure. We can show you movements to try, such as crossing the legs while standing and tensing the leg, abdominal, and buttock muscles.

Practice with your child. Teach them to use exercise as soon as they start feeling faint.

Home Treatment

If your child faints often, make sure you and other caregivers know their triggers and what to do if they faint.

You can help by:

  • Catching your child (if possible) to prevent falling. 
  • Laying your child flat after they pass out or placing a small child on your lap.
  • Loosening belts or other tight clothing to help blood flow. 
  • Raising their feet about 12 inches, to help blood flow to their brain. 

Make sure your child lies down for 10 to 15 minutes after they wake up from fainting, so they won’t faint again. 

Do not:

  • Raise your child’s head with a pillow or another item.
  • Shake your child to try to wake them.
  • Give water or food while they’re unconscious.

After a fainting spell:

  • Reassure and comfort your child.
  • Let them rest until they recover from feeling dizzy or tired.
  • Contact your child's doctor to schedule an appointment. 

Call 911 or go to the nearest hospital if after fainting, your child: 

  • Isn’t breathing.
  • Doesn’t wake up quickly.
  • Is seriously injured during a fall.

If you have an emergency medical condition, call 911 or go to the nearest hospital. An emergency medical condition is any of the following:
(1) a medical condition that manifests itself by acute symptoms of sufficient severity (including severe pain) such that you could reasonably expect the absence of immediate medical attention to result in serious jeopardy to your health or body functions or organs; (2) active labor when there isn't enough time for safe transfer to a Plan hospital (or designated hospital) before delivery, or if transfer poses a threat to your (or your unborn child's) health and safety, or (3) a mental disorder that manifests itself by acute symptoms of sufficient severity such that either you are an immediate danger to yourself or others, or you are not immediately able to provide for, or use, food, shelter, or clothing, due to the mental disorder.

This information is not intended to diagnose health problems or to take the place of specific medical advice or care you receive from your physician or other health care professional. If you have persistent health problems, or if you have additional questions, please consult with your doctor. If you have questions or need more information about your medication, please speak to your pharmacist. Kaiser Permanente does not endorse the medications or products mentioned. Any trade names listed are for easy identification only.