Syncope and passing out: what should you know?

A person may first feel faint, weak, hot, sick, sweaty, or visually disconnected. They may slump or fall and then become alert after being placed safely on the ground. Passing out can follow a reflex response to pain, fear, heat, prolonged standing, dehydration, or an empty stomach. Anaemia and low glucose can contribute; a heart-rhythm condition such as atrial fibrillation is another possibility that should not be overlooked. These links do not diagnose the person who has passed out. The details of the event and health history matter.

Lower the person gently, keep them flat, and raise their legs if there is no suspected injury. Check breathing and remove nearby hazards. If they are breathing but not waking, place them in the recovery position and call emergency services. Do not shake them, force them upright, or give anything by mouth while unconscious. After they recover, let them rest, offer a drink only when fully alert, and help them stand gradually. A medical review is appropriate for a first or unexplained event.

Call emergency services if consciousness does not return promptly, breathing is abnormal, the person has chest pain, severe shortness of breath, a serious head injury, new weakness, speech trouble, or ongoing confusion. Treat an episode during exercise, while lying down, or after palpitations as urgent. Recurrent passing out, collapse without warning, or a history of heart disease also warrants prompt assessment. Do not drive until a clinician has advised that it is safe.

What might the posture, trigger, warning symptoms, and recovery tell us? Do I need an ECG, blood tests, or blood-pressure checks? Which warning signs should prompt emergency help if this happens again?