Dizziness and fainting in children Dizziness and fainting in children  

Fainting, also called syncope, happens when a person suddenly loses consciousness and then rapidly returns to normal.

Signs and symptoms of fainting

Right before fainting, your child might:

  • feel dizzy or light headed
  • feel weak
  • see dark spots
  • hear muffled sounds
  • feel nauseous (want to vomit​)
  • feel hot
  • feel cold and clammy
  • become pale
  • start to sweat.

Causes of fainting

A child can faint for a number of possible reasons. The most common cause of fainting is a temporary drop in blood pressure. Fainting because of low blood pressure is often called a “vagal” or “vasovagal” episode.

A child is more likely to have a drop in blood pressure if they:

  • are dehydrated (from excessive sweating, diarrhea or vomiting)
  • have not been eating
  • have been standing still for a long time
  • are unwell.

Other common causes of fainting

A child might also faint if they

Fainting may be more likely in a closed setting or one that is hot and humid. It may also happen in response to a stimulus that is noxious (unpleasant or potentially harmful), such as a very bad smell or the sight of blood or a needle.

More serious medical causes of fainting

Fainting can sometimes have more serious causes. These include:

  • an underlying heart condition or heart rhythm disturbance
  • exposure to a medication, toxin or drug
  • hypoglycemia (low blood sugar)
  • anemia (low levels of iron in the blood)
  • pregnancy
  • anaphylaxis (allergic reaction).

Fainting during exercise or exertion (carrying or pushing something heavy) can be a sign of an underlying condition and should be discussed with your child’s doctor.

Conditions that appear similar to fainting

There are some conditions that make it appear that a child is fainting when, in fact, something else is wrong. These mimics of fainting include:

How to help your child if they have fainted

  • Check to make sure your child is breathing. If necessary, call 911.
  • Keep your child lying down or, if possible, sit them forward with their head between their knees.
  • Loosen any tight clothing around your child’s neck.
  • Make an appointment with your child’s doctor and explain exactly what happened.

When to see a doctor

See your child’s doctor to identify the cause of a fainting episode.

Call 911 right away if your child:

  • has stopped breathing
  • does not become alert right away
  • has changes in their speech, vision or ability to move.

Key points

  • Fainting is a sudden and temporary loss of consciousness with a rapid return to normal.
  • Your child may feel dizzy, nauseous, hot or cold right before they faint. Their face may also go pale.
  • The most common cause of fainting is a drop in blood pressure. Other, more serious, causes include an underlying heart condition, low blood sugar or anemia.
  • See your child’s doctor to discuss the possible cause of any fainting episode. Call 911 right away if your child has stopped breathing or does not “come around” shortly after fainting.
Elizabeth Berger, BA, MD, FRCPC, FAAP, MHPE