What should you know about someone fainting?

Fainting, also called syncope, is a brief loss of consciousness caused by a temporary reduction in blood flow to the brain. A person may feel warm, sweaty, nauseated, dizzy, or have blurred vision before collapsing. Triggers can include standing for a long time, heat, pain, emotional shock, dehydration, or not eating. Some episodes relate to conditions such as Anaemia, Atrial Fibrillation, Dehydration, or Hypoglycaemia. Fainting can also happen without warning, so the fall itself may cause injury.

Clear nearby objects and lower the person gently onto their back. Check whether they respond and are breathing normally. Loosen tight clothing, keep them warm, and raise their legs when there is no suspected leg, hip, back, or neck injury. Do not give food, drink, or tablets until they are fully awake, and do not make them sit or stand quickly. If breathing is absent or abnormal, call emergency services and begin the recommended resuscitation steps.

Call emergency services if the person does not wake promptly, has trouble breathing, chest pain, a severe headache, a seizure, confusion, a serious injury, or fainted during exercise. Urgent assessment is also needed for repeated episodes, a racing or irregular heartbeat, pregnancy, diabetes, or known heart disease. Arrange a medical review after a first unexplained faint, even when recovery is quick; the clinician may ask about posture, food and fluid intake, medicines, warning symptoms, and family history.

Ask what might have triggered the episode, whether medicines or fluid intake could contribute, and whether you need an examination, heart tracing, or blood tests. Record what the person was doing, any warning symptoms, how long they were unresponsive, and how they felt afterward.