Fainting / Syncope in Children and Teenagers

Fainting overview
Child being assessed

What is Fainting?

A faint (blackout/syncope) is a sudden loss of consciousness—not usually associated with jerking movements. The medical term for a faint is syncope.

The most common cause in children and teenagers is a transient fall in blood pressure (vasovagal syncope). This may occur after prolonged standing, particularly on a hot day or in dehydrated individuals. Rarely, it can be due to an underlying heart condition, so assessment by a clinician is advisable.

Symptoms & Warnings

Common warnings include feeling light-headed, queasy (nauseous), loss of hearing, or a sensation of everything becoming dark. They may appear pale or clammy.

Important: If a child faints without warning or during exercise, a more urgent assessment is required.

Diagnosis & The Tilt Test

An Echocardiogram and ECG are performed to exclude structural heart disease. Depending on history, a 24-hour tape or exercise test may be used.

The Tilt Test: Involves monitoring heart rate and blood pressure while tilted forward on a specialized table. It helps diagnose vasovagal fainting tendencies in a safe, controlled environment.

Treatment & Outlook

For simple fainting (vasovagal syncope), the primary treatment is increased fluid and salt intake and regular meals. If an underlying heart condition is found, specific treatment will be required.

The outlook for children with simple fainting is excellent. Most children outgrow it or learn to control their symptoms.

Tilt Test
Tilt Testing

A specialized test to evaluate blood pressure response and fainting triggers.

Expert Care

Dr Naqvi is the Paediatric Aortopathy Marfan Lead at the Royal Brompton Hospital and an expert in fainting disorders.

Disclaimer: The opinions and facts shown in this article are as accurate and up to date as possible but are provided as general resources. This is not a substitute for individual assessment. Always take advice from a paediatric cardiologist familiar with the particular person.