What should you know about people fainting?

Fainting can follow prolonged standing, heat, pain, fear, dehydration, not eating, or a sudden drop in blood pressure. Some medicines and health problems can also contribute, including Anaemia, Hypoglycaemia or an abnormal heart rhythm such as Atrial Fibrillation. A sudden collapse can also be caused by something other than fainting, so the circumstances matter.

Before an episode, a person may feel warm, sweaty, nauseated, light-headed or have tunnel vision. They usually recover after lying down, but confusion, weakness, injury or ongoing symptoms need assessment.

Lay the person flat and raise their legs if there is no serious injury or breathing problem. Check that they are breathing, loosen tight clothing, keep them warm and protect the head. Do not give food or drink until they are fully awake, and do not make them stand quickly.

If they do not regain consciousness promptly, are not breathing normally, or have a serious injury, call emergency services and follow the dispatcher’s instructions. Once recovered, arrange medical review after a first episode, repeated fainting, or a collapse without a clear trigger.

Call emergency services for fainting during exercise, chest pain, palpitations, severe breathlessness, seizure-like movements, sudden weakness, speech trouble, pregnancy, major bleeding, a head injury, or a person who remains confused or unresponsive. Urgent assessment is also needed when the episode occurs while lying down or without warning.

Tell the clinician what happened before, during and after the episode, including posture, food and fluid intake, medicines, injuries and recovery. Ask whether you need heart monitoring, blood tests or review of possible dehydration or low blood sugar.