svenimento

Svenimento, known in English as syncope or fainting, is a transient loss of consciousness caused by a temporary reduction in cerebral blood flow. The event is usually brief and followed by a rapid recovery, with return to baseline function once perfusion to the brain is restored. The term is used in medical contexts to describe a specific clinical phenomenon rather than a seizure or coma.

Most cases are reflex (vasovagal) syncope, often triggered by emotional distress, pain, fear, or prolonged standing. Other common categories include situational syncope, related to activities such as coughing, urination, or defecation; orthostatic hypotension from dehydration, medications, or autonomic dysfunction; and cardiac syncope due to arrhythmias or structural heart disease. Rarely, neurologic disorders or metabolic disturbances can cause loss of consciousness mistaken for syncope.

Prodromal symptoms may precede the event, including lightheadedness, dizziness, nausea, pallor, sweating, or blurred vision. Onset is typically sudden, with loss of consciousness followed by a prompt recovery. Most people regain orientation quickly, though confusion can occur briefly after awakening.

Diagnosis relies on clinical history and physical examination, supported by measurements of vital signs and orthostatic blood pressure. Electrocardiography is routinely used to detect arrhythmias or cardiac conditions. Further testing, such as echocardiography, ambulatory monitoring, or tilt-table testing, is guided by the suspected underlying cause.

Management focuses on preventing recurrence and addressing the cause. Acute care involves placing the person flat, loosening restrictive clothing, elevating the legs to improve cerebral perfusion, and monitoring for injury. Long-term strategies for vasovagal or orthostatic syncope include hydration, appropriate salt intake when advised, physical counterpressure maneuvers, gradual position changes, and review of medications or treatable conditions.

Prognosis is generally favorable, especially for noncardiac causes. Persistent or exertional syncope, or syncope with heart disease, warrants specialist evaluation. Education and avoidance of triggers reduce recurrence risk.