Vasovagal Syncope: This is the most common cause of syncope in children, often triggered by pain, fear, or prolonged standing. It's characterized by a brief loss of consciousness due to a sudden decrease in blood flow to the brain.

Breath-Holding Spells: Common in infants and toddlers, these spells can lead to syncope. They are usually triggered by emotional distress or pain.
Seizures: Though not typically the first consideration for syncope, seizures can present with loss of consciousness and may be confused with syncope.
Orthostatic Hypotension: This condition involves a significant drop in blood pressure upon standing, which can lead to syncope. It might be seen in children who are dehydrated or have autonomic dysfunction.

Cardiac Anomalies (e.g., Long QT Syndrome, Hypertrophic Cardiomyopathy): These conditions can lead to life-threatening arrhythmias and are critical to identify. Though less common, they are potentially fatal if missed.
Intracranial Hemorrhage or Mass: Though rare, any form of intracranial pathology can cause syncope and is crucial to rule out due to the high risk of severe outcomes.
Infections (e.g., Meningitis, Sepsis): Severe infections can lead to syncope among other symptoms and require immediate medical attention.

Metabolic Disorders: Certain metabolic conditions can lead to episodes of syncope, though they are less common.
Neurocardiogenic Syncope with Prolonged Asystole: A rare form of vasovagal syncope that can lead to more prolonged loss of consciousness.
Subclavian Steal Syndrome: A rare condition where there's a reversal of blood flow in the vertebral artery due to a stenosis or occlusion of the subclavian artery, potentially leading to syncope.