A sudden and transient loss of consciousness that is assoicated with a loss of postural tone, and resolves spontaneously and completely without intervention

Occurs due to a disruption of blood flow to the brain

Vasovagal episode:

Vagus nerve recieves strong stimulus (emotional event, painful sensation, change in temp) - stimulating the PSN system, dilating blood vessels = drop in the blood pressure in cerebral circulation = hypoperfusion of brain tissue and subsequent syncope

Aetiology

Primary syncope (simple fainting):

• Dehydration
• Missed meals
• Extended standing in a warm environment, such as a school assembly
• A vasovagal response to a stimuli, such as sudden surprise, pain or the sight of blood

Secondary causes:

• ACS
• Arrhythmias
• Valvular heart disease
• Hypoglycaemia
• Dehydration
• Anaemia
• Infection