What should you know about frequent syncope?

Syncope is a brief loss of consciousness caused by reduced blood flow to the brain, followed by spontaneous recovery. A reflex response, standing suddenly, heat, pain, dehydration, or missed food can contribute. Anaemia may reduce oxygen delivery, while atrial fibrillation and other rhythm problems can affect the heart's output. Hypoglycaemia can also cause loss of consciousness, particularly in someone using glucose-lowering medicine. The trigger, position, warning sensations, recovery, and any injury help a clinician work out the cause.

Lie flat with the legs raised if someone feels faint, loosen tight clothing, and move away from hazards. Do not stand quickly after recovering. Arrange a medical review for repeated episodes and bring a description from anyone who witnessed the event. Until the cause is clearer, take care with driving, heights, swimming alone, and machinery. Keep prescribed medicines available and mention recent illness, fluid loss, dietary changes, or palpitations.

Call emergency services if fainting occurs during exertion, with chest pain, severe breathlessness, a racing or irregular heartbeat, seizure-like movements, significant injury, prolonged confusion, or failure to recover promptly. Urgent assessment is also needed for fainting while sitting or lying down, a new episode in someone with known heart disease, or repeated episodes close together. These warning signs indicate risk; they do not identify a single cause.

Ask what checks are needed for blood pressure, heart rhythm, blood count, and glucose. Discuss whether dehydration, anaemia, hypoglycaemia, or atrial fibrillation could fit the event, and ask which activities should be avoided until review is complete.