What should you know about vago syncope?

There is no separate standard diagnosis commonly called vago syncope. People often use the phrase when they mean vasovagal syncope. A trigger such as pain, fear, heat, standing still or a procedure can activate the vagus nerve reflex. Blood pressure may fall and the heart rate may slow, leading to light-headedness or a short blackout.

Warning signs can include nausea, sweating, pallor, a feeling of heat, tunnel vision and weakness. A faint that looks similar can have another cause. Dehydration, low blood sugar, anaemia or an abnormal heart rhythm such as Atrial Fibrillation should be considered when the story does not fit a typical reflex episode.

When warning symptoms begin, get down safely rather than trying to walk. Lie flat with your legs raised, or sit and lower your head if needed. Once awake, take time before standing and have someone stay with you. Note what happened immediately before the event, whether there was a warning, how long you were unresponsive and how you felt afterwards. This information helps a clinician assess the event.

Get emergency help when recovery is delayed, breathing is abnormal, there is chest pain, a serious injury, a seizure, or new confusion, weakness or speech difficulty. Medical review is also needed for a first faint, a faint during exertion or while lying down, repeated blackouts, or an episode with palpitations. Do not assume the label explains the event before it has been assessed.

Ask whether the episode sounds vasovagal, whether blood pressure and heart rhythm need checking, which warning signs should prompt you to lie down, and how to reduce your personal triggers.