Convulsive syncope: what should you know?

Before fainting, a person may feel warm, nauseated, light-headed, or have narrowing vision. They can briefly lose consciousness and show a few jerking movements as blood flow falls, then begin to respond as they lie flat. Dehydration, standing for a long time, pain, or a sudden drop in blood pressure can contribute. Anaemia, low blood sugar, and an abnormal heart rhythm such as atrial fibrillation are other possibilities. The difference from a seizure is not always clear from memory alone.

Lay the person flat and raise the legs if there is no injury or breathing problem. Loosen tight clothing, check breathing, and keep the area clear. Do not make them stand quickly or give food and drink until they are fully alert. If they are not breathing normally, start emergency first aid and call for help. Note the posture, warning symptoms, colour change, duration of unresponsiveness, movements, injuries, and recovery.

Call emergency services if the person does not wake promptly, has chest pain, palpitations, severe breathlessness, a serious injury, prolonged jerking, or faints during exercise. Urgent review is also needed for a first episode, fainting while lying down, repeated episodes, a family history of sudden cardiac death, or new weakness or speech trouble. Until assessed, avoid driving, swimming alone, heights, and operating machinery.

Ask whether the episode fits reflex fainting, whether heart monitoring or blood tests are needed, and how dehydration, anaemia, glucose, medicines, or rhythm problems could contribute. Bring a witness account and ask when normal activities can safely resume.