Synkope

Synkope, commonly referred to as fainting, is a sudden but brief loss of consciousness with a temporary loss of postural tone, followed by spontaneous recovery. It results from a transient reduction in cerebral perfusion and is distinct from seizures, coma, or deliberate collapse. Most episodes are self-limited and resolve within seconds to a couple of minutes.

The main types are reflex (vasovagal) syncope, orthostatic hypotension–related syncope, and cardiac syncope due to heart disease or arrhythmias. Less common causes include neurologic conditions or medication effects. Triggers for reflex syncope include prolonged standing, emotional distress, pain, or heat. Orthostatic syncope arises from a failure to maintain blood pressure when standing, often related to dehydration, volume depletion, or antihypertensive medications. Cardiac syncope carries a higher risk because it may reflect dangerous arrhythmias or structural heart disease such as aortic stenosis or cardiomyopathy.

Evaluation starts with a careful history and physical examination, emphasizing symptoms before, during, and after the event, recovery time, and any warning signs. Orthostatic vital signs and an electrocardiogram are commonly obtained. Further testing (ambulatory rhythm monitoring, echocardiography, exercise testing, or tilt-table testing) is guided by findings and suspected cause. It is important to distinguish syncope from seizures or metabolic disturbances.

Management focuses on preventing recurrence and treating the underlying cause. Immediate first aid includes placing the person on their back with legs elevated, loosening restrictive clothing, and ensuring airway safety. Counseling covers safety measures, hydration, and identifying triggers. Treatment varies by type: reflex syncope may involve performable counterpressure maneuvers and lifestyle adjustments; orthostatic syncope often requires medication review and volume expansion; cardiac syncope requires specialist cardiology assessment and targeted therapy. Prognosis is generally favorable for reflex and orthostatic forms but depends on the underlying cardiac condition.