I am fainting: what should I know?

A hot environment, prolonged standing, missed meals, dehydration, pain, or a sudden drop in blood pressure can lead to fainting. Anaemia may reduce oxygen delivery and contribute to light-headedness. Atrial fibrillation and other heart rhythm problems can also cause collapse, sometimes without much warning. Record what happened before, during, and after the episode, including palpitations, chest symptoms, injury, or confusion.

If you feel faint, lie down and raise your legs if possible. Loosen tight clothing, move away from heat, and do not stand quickly. Someone who has fainted should be placed safely on their side if breathing normally, with the area cleared of hazards. Do not give food or drink until they are fully alert.

Call emergency services if the person is not breathing normally, does not wake promptly, has chest pain, severe breathlessness, a seizure, a serious injury, or new weakness or speech trouble. Seek urgent assessment when fainting happens during exercise, while sitting or lying down, after a racing heartbeat, or repeatedly. Arrange a medical review after any unexplained faint.

Ask whether you need heart monitoring, blood tests, or a medication review. Tell the clinician about fluid intake, meals, bleeding, heavy periods, family history of sudden cardiac death, and any warning sensations such as nausea, sweating, or palpitations.