Causes of fainting
Fainting can happen for a number of reasons. The most common cause of fainting is a temporary slowing of the heart rate and a drop in blood pressure. This type of fainting is 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
- are frightened
- are in severe pain
- stand up too fast
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.
Conditions that appear similar to fainting
There are some conditions that look like fainting, but the loss of consciousness is actually caused by something else. These mimics of fainting include:
- an underlying heart condition or heart rhythm disturbance
- exposure to a medication, toxin or drug
-
hypoglycemia (low blood sugar)
-
anaphylaxis (allergic reaction)
-
seizures
- migraine
headaches
- hyperventilation
- panic attacks
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 health-care provider.