What should you know about standing in one place too long fainting?

Fainting, also called syncope, is a brief loss of consciousness caused by reduced blood flow to the brain. Standing still removes the regular leg-muscle movement that helps push blood back towards the heart. Heat, crowded spaces, pain, fear, dehydration, hunger, and exhaustion can make this response more likely. Warning symptoms may include warmth, sweating, nausea, yawning, grey or narrowing vision, ringing in the ears, and weakness. Fainting can also have other causes, including anaemia, dehydration, hypoglycaemia, or an abnormal heart rhythm such as atrial fibrillation. The event needs context, especially if it happened without warning.

At the first warning, lie down and raise your legs, or sit with your head lowered if lying down is not possible. Move away from heat and ask someone to stay with you. Once fully alert, take small sips of fluid if you can swallow safely and avoid standing quickly. Someone who has fainted should be placed on their back with the airway clear; do not give food or drink until they are awake. Record what happened, including posture, warning symptoms, recovery, food and fluid intake, and any medicines. Arrange medical assessment after a first unexplained episode or if episodes recur.

Call emergency services if the person does not wake promptly, has trouble breathing, chest pain, a severe headache, seizure-like movements, a serious injury, or new weakness or speech trouble. Urgent assessment is also needed when fainting occurs during exercise, while lying down, with palpitations, or without any warning. Do not assume prolonged standing was the cause until concerning features have been considered.

Ask whether you need blood pressure and pulse checks, an electrocardiogram, or blood tests. Tell the clinician about family heart history, bleeding, heavy periods, diabetes medicines, skipped meals, recent illness, and any injury during the episode.