nearsyncope

Near-syncope, also called presyncope or pre-fainting, is a transient sensation of impending loss of consciousness due to reduced blood flow to the brain. People typically describe dizziness, lightheadedness, blurred vision, weakness, sweating, nausea, or a feeling of warmth. Unlike true syncope, it does not involve a loss of consciousness.

Common causes include vasovagal (fainting) reactions, orthostatic hypotension, dehydration, and cardiac issues such as arrhythmias or structural heart disease. Medications that lower blood pressure or affect heart rate, excessive heat, prolonged standing, anemia, and anxiety can contribute. The underlying mechanism is usually a temporary drop in cerebral perfusion from reductions in heart output or inadequate blood return to the heart.

Evaluation centers on distinguishing near-syncope from other causes of dizziness and ruling out serious conditions. A medical history and physical exam are essential, with attention to red flags such as chest pain, shortness of breath, exertional symptoms, fainting with exertion, or trauma. Tests may include orthostatic vital signs, an electrocardiogram, and targeted investigations (e.g., echocardiography, Holter monitoring) based on symptoms. Tilt-table testing may be used to evaluate suspected vasovagal syncope.

Management focuses on treating underlying causes and reducing recurrence. Hydration, adequate salt intake in appropriate individuals, and avoidance of triggers are common strategies. Physical counterpressure maneuvers, gradual position changes, and, when applicable, adjustment of medications can help. Education about warning signs and safety measures to prevent injury during episodes is important. Seek urgent care if symptoms are accompanied by chest pain, palpitations, shortness of breath, or prolonged loss of consciousness. The prognosis varies with cause but near-syncope is usually a warning sign rather than a final diagnosis.