What should you know about post syncope?

Syncope is a brief loss of consciousness caused by reduced blood flow to the brain, followed by recovery. Triggers can include standing suddenly, heat, pain or emotional stress, but fainting can also relate to dehydration, low blood sugar, anaemia or an abnormal heart rhythm such as atrial fibrillation. The circumstances matter: an episode during exercise, without warning, or while lying down needs careful assessment.

Lie flat and raise your legs if possible. Loosen tight clothing, move away from heat and do not stand quickly. Once fully alert, take small sips of fluid and eat if you may not have eaten, unless a clinician has advised otherwise. Record what happened before, during and after the event, including posture, warning symptoms, injuries, medicines and witness observations. Arrange medical review before returning to driving or hazardous work.

Call emergency services if the person is not waking, has trouble breathing, chest pain, severe headache, new weakness, confusion, a serious injury or a sustained irregular heartbeat. Urgent assessment is also needed for fainting during exercise, repeated episodes, fainting without warning, or a family history of sudden cardiac death. Even a first uncomplicated episode deserves a clinician’s review to identify reversible causes.

Could dehydration, anaemia, low blood sugar or a heart rhythm explain this episode? Do I need an ECG or blood tests? When is it safe to drive, exercise and work at height?