What should you know about sneeze syncope?

A forceful sneeze briefly changes pressure inside the chest. That can reduce blood returning to the heart for a moment, while a reflex may widen blood vessels or slow the heartbeat. If the brain receives less blood briefly, light-headedness or loss of consciousness can follow.

Other contributors can include dehydration, low blood glucose, anaemia, or an abnormal heart rhythm. The timing does not prove the sneeze was the only cause, so a first episode or repeated episodes should be reviewed.

At the first sign of dizziness, sit or lie down immediately and avoid driving, climbing, or standing suddenly. If someone faints, protect them from injury, check breathing, and place them on their side if they are breathing but do not wake quickly. Keep a record of the sneeze, warning symptoms, duration, and recovery.

Call emergency services if fainting follows chest pain, severe breathlessness, a racing or irregular heartbeat, seizure-like movements, serious injury, or failure to wake normally. Urgent assessment is also needed when fainting happens during exertion or occurs repeatedly.

Ask whether you need a heart rhythm check, blood tests, or review of hydration and glucose. Tell the clinician about palpitations, medicines, recent illness, bleeding, and any family history of sudden cardiac problems.