Fainting in Children


Fainting refers to a sudden, brief loss of consciousness, medically known as syncope. Fainting occurs when your child’’s blood pressure drops quickly, which reduces blood flow and oxygen to the brain. Your child may wake up within seconds, or it may take 1 to 2 minutes for him or her to recover.

Roughly 1 in 7 children will faint at some point before the end of adolescence. Children who experience fainting often outgrow it.

There are many causes of fainting, most of which are not serious. Fainting can occur even if your child is healthy. In some children, the body reacts abnormally to certain triggers, such as dehydration, prolonged standing, the sight of blood, or extreme emotional distress. Your child’’s blood pressure suddenly drops and he or she may feel dizzy or lightheaded before passing out.

Although fainting is usually harmless, an episode can be frightening for you and your child, especially if fainting occurs more than once. We can help determine why your child is fainting and how to prevent or treat future episodes.


Fainting occurs when there is not enough blood flow to your child’’s brain. Blood contains oxygen, so when something interrupts the normal flow of blood to the brain, less oxygen is also sent to the brain.

There are various causes of fainting, including some that are serious, such as an abnormal heartbeat or seizures. However, the most common causes of fainting in children are not dangerous. Even so, we recommend you see your child’’s doctor if your child faints.

More Serious Causes of Fainting

Fainting is usually divided into 2 categories: cardiac (heart-related) syncope and non-cardiac syncope. Cardiac syncope is the most dangerous type of fainting. It can be a sign of a serious problem, such as a problem with the electrical system of the heart or a structural abnormality in the heart. A heart condition can interfere with the heart’’s ability to pump blood to your child’’s brain.

Children very rarely experience fainting related to a heart problem. If they do, the condition may be caused by a congenital heart defect that was present at birth or genetic electrical heart abnormalities. Children with a heart condition may experience other symptoms, such as chest pain or heart palpitations, prior to fainting.

Sometimes, seizures are confused with syncope. Both can occur suddenly and cause your child to lose consciousness. But seizures are caused by abnormal electrical activity in the brain, not by decreased blood flow to the brain. A seizure disorder does not cause symptoms ahead of time, such as lightheadedness or blurry vision. In addition, seizures cause a child to lose consciousness for a longer period of time than with syncope. Seizures can be a serious medical condition.

Less Serious Causes of Fainting

Although seeing your child faint can be scary, most causes of syncope are not serious. The most common type of non-cardiac syncope in children is vasovagal syncope.

Also called neurocardiogenic syncope, vasovagal syncope occurs when your child’’s body reacts to a trigger by slowing the heart rate and widening (dilating) the blood vessels. This reduces the heart’’s ability to pump blood to the brain and causes your child to lose consciousness for a very short time until blood starts circulating normally again.

Common triggers of vasovagal syncope in children include:

  • Dehydration
  • Sudden fright, anger, or frustration, which can result in a breath-holding spell, a period when a child stops breathing for up to 1 minute
  • Standing for a long period of time or standing up too fast
  • Sudden pain or injury
  • Emotional or physical stress
  • Sight of blood
  • Heat exposure
  • Crowding

Some causes of non-cardiac syncope are more serious than others. We recommend you contact your child’’s doctor the first time he or she faints to review how it happened and to determine the cause.


Your child may experience symptoms before and after fainting. At first, your child may feel uncomfortable and feel the need to sit or lie down. He or she may then experience more specific warning signs, such as:

  • Dizziness or lightheadedness
  • Weakness
  • Nausea
  • Feeling warm
  • Blurred vision
  • Tunnel vision (seeing only what is in front of you)
  • Pale skin
  • Changes in hearing
  • Forceful heartbeat
  • Hyperventilation
  • Sweating

How long symptoms last varies from child to child, but, on average, symptoms begin 30 to 60 seconds before fainting. After your child wakes up, he or she may continue to experience symptoms caused by low blood pressure, such as dizziness, confusion, or fatigue. It is important your child remain lying down for a period of time because getting up too quickly may cause him or her to faint again.

As soon as your child begins to experience symptoms, it is important for him or her to lie down or sit with the head bent forward between the knees. This can help blood flow more easily to your child’’s brain and possibly prevent fainting.

If your child faints during exercise or experiences heart palpitations or chest pain before fainting, this could be a sign of a serious condition that requires immediate medical attention.

After a fainting spell, reassure and comfort your child. If your child faints regularly, make sure your child’’s caregivers understand the cause of your child’’s fainting and how to manage it.


Whether your child faints once or frequently, diagnosing the cause helps determine how to prevent or treat future episodes.

We first review your child’’s medical history, including any current medications. It is also important to know if there is a family history of congenital heart disease, cardiomyopathies (diseases of the heart muscle that may be genetic) or electrical heart problems, seizures, or fainting during childhood. We also ask questions about the events that led to your child fainting, including:

  • What was your child doing immediately before fainting? Did your child faint during exercise or while eating?
  • What was the environment like when your child fainted?
  • What symptoms did your child experience before fainting?
  • Was your child dehydrated before fainting?
  • How long did your child remain unconscious?
  • How often does your child faint?
  • Did you or someone else witness your child faint? Can you describe what happened? Was your child standing, sitting, or lying down?

We perform a physical exam, which includes checking your child’’s blood pressure and heart rate.

We also listen to your child’’s heart with a stethoscope to check for irregularities in your child’’s heart rhythm. A medical history and physical exam are often enough to diagnose the cause of syncope.

In some cases, additional testing may be needed. Tests may include:

  • Electrocardiogram (ECG/EKG). This test checks the electrical activity of your child’’s heart. It can detect conditions that cause an irregular heartbeat. An EKG is done in children who experience frequent fainting episodes and children who faint during exercise.
  • Echocardiogram. An echocardiogram is an ultrasound test that shows the size and structure of your child’’s heart and allows us to view the movement of the heart valves and pumping chambers. We can also see how blood moves through your child’’s heart. The test can help determine whether fainting is caused by a heart problem.
  • Holter monitor. Also called a continuous monitor, a Holter monitor can help diagnose fainting episodes that occur intermittently. Unlike a standard EKG which records the heart’’s electrical activity for only seconds, a Holter monitor constantly records your child’’s heartbeat for 24 to 48 hours. Three to 5 electrodes attached to your child’’s chest are connected to a monitor, which is carried in a pocket or worn on a belt or shoulder strap. We ask you or your child to write down activities and any symptoms he or she experiences while wearing the monitor.
  • Event monitor. An event monitor records your child’’s heartbeat only during symptoms. An event monitor may be used instead of a Holter monitor if your child’’s fainting episodes occur less frequently than once a day.
  • Exercise stress test. While your child is exercising on a treadmill or stationary bike, we take EKG readings and monitor your child’’s blood pressure. This test is usually not done in children under age 10.
  • Cardiac catheterization. This test produces clear images of your child’’s heart and checks blood flow through the heart. We guide a narrow, flexible tube called a catheter to the heart through a blood vessel in the groin or arm. When it reaches the heart, the catheter releases a special contrast dye that enables detailed X-ray imaging of the heart and blood vessels. This procedure may be done to pinpoint the location of an irregular heart rhythm (arrhythmia).
  • Blood tests. We may test your child’’s blood to check whether a low red blood cell count (anemia) is causing fainting.
  • Electroencephalogram (EEG). To determine if fainting is caused by a seizure disorder, an EEG may be done to detect problems with the brain’’s electrical activity. Small electrodes attached to the scalp measure electrical signals as they move through the brain.


Treatment for fainting depends on its underlying cause.

For non-cardiac syncope, we may recommend the following:

  • Learn your child’’s fainting triggers and try to avoid those situations. With vasovagal syncope, you can predict when your child may pass out by working with us to pinpoint his or her triggers. Maybe your child passes out when overheated or during extreme periods of frustration. Your child may benefit from minimizing the amount of time spent outdoors during the hottest part of the day. For periods of significant frustration that can lead to a breath-holding spell, we talk with you about strategies to manage your child’’s frustration.
  • Increase fluid and salt intake. Fainting is often caused by a drop in blood pressure, so drinking plenty of fluids (water, juices, milk, or other non-caffeinated beverages) and increasing the amount of salt in your child’’s diet increases the total volume of blood in the body and increases blood pressure. Teenagers should drink 2 to 3 liters of fluid each day. It is especially important that your child drink fluids before and during exercise and sports.
  • Take action when warning signs occur. If your child starts to feel dizzy or experiences any other symptoms of fainting, ask your child to stop what he or she is doing and lie down or sit with the head lowered between the knees. Gravity will help blood circulate to your child’’s brain. Once your child no longer feels faint, he or she can stand up slowly.
  • Teach your child to use physical counter-pressure maneuvers. When your child feels a fainting spell coming on, a few simple counter pressure exercises can help raise blood pressure and prevent fainting. For example, the leg crossing maneuver involves crossing the legs while standing and tensing the leg, abdominal, and buttock muscles. We show you other physical maneuvers to practice with your child.

Avoiding fainting triggers and using other prevention techniques are often all that is needed to treat fainting.

For cardiac syncope, the more serious type of fainting, we may need to treat the heart condition that is causing your child to faint. Medications can often control heart rhythm abnormalities in children. In some cases, a pacemaker, defibrillator, catheter ablation, or surgery may be needed.

What to do when your child faints

If your child faints, there are ways you can help.

  • If possible, help prevent a fall by catching your child.
  • After your child passes out, make sure he or she is lying flat. Lay a small child down on your lap.
  • Loosen belts or other tight clothing that may restrict blood flow.
  • Elevate your child’’s feet about a foot to help move the flow of blood back to the brain.
  • Make sure your child stays lying down for 10 to 15 minutes after waking up because rising too quickly can cause another fainting spell.
  • Contact your child’’s doctor to schedule an appointment.
  • Call 911 if your child is not breathing, does not wake up quickly after fainting, or is seriously injured during a fall.

There are also actions you should avoid when your child faints. Do not elevate the head with a pillow or other item, do not shake your child to try to revive him or her, and do not give water or food to someone who is unconscious.

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.