Fainting from fear: what to know

A frightening sight, sudden shock or intense distress may activate a reflex involving the nervous system. Heart rate and blood pressure can then fall. Warning symptoms may include warmth, sweating, nausea, ringing in the ears, grey or blurred vision and weakness.

Fear is a possible trigger, not a diagnosis for every collapse. Dehydration, anaemia, low blood sugar and an abnormal rhythm such as Atrial Fibrillation can also cause faintness. Events without warning, during exertion or in a different setting deserve separate assessment.

Move away from danger and lie flat straight away; tell someone nearby what you feel. If lying down is not possible, sit and lower your head between your knees. Slow your breathing without forcing deep breaths, and avoid standing until the warning has passed completely.

A trusted person should keep you safe, check your breathing and avoid giving drinks while you are unconscious. Once fully alert, take fluids and a light snack if appropriate for you.

Call emergency services for chest pain, severe breathing difficulty, a serious injury, prolonged unconsciousness, seizure-like activity, or failure to return to your usual state. Seek medical review when episodes recur, happen without a clear emotional trigger, or occur while exercising or lying down.

Ask whether the pattern fits a reflex faint, whether blood pressure and heart rhythm should be checked, and how to manage future exposure to the trigger. Discuss panic symptoms, medicines, hydration and any family history of sudden cardiac death.