I Keep Fainting: What Should You Know?

Fainting, also called syncope, happens when the brain briefly receives too little blood flow. It can follow prolonged standing, heat, emotional stress, pain, dehydration, or a sudden drop in blood pressure. Low blood glucose can also cause weakness, sweating, confusion, or collapse. Anaemia may contribute to tiredness, breathlessness, dizziness, or fainting. Less commonly, an abnormal heart rhythm such as atrial fibrillation or another heart problem may be involved. The event itself does not reveal the cause, so details before, during, and after each episode are useful.

At the first sign of light-headedness, lie flat with your legs raised if possible, or sit with your head lowered. Loosen tight clothing, move away from heat, and do not drive, climb, or operate machinery until you have been assessed. Once fully alert, drink fluids if you can swallow safely and have no medical restriction. Tell someone what happened and record your position, activity, warning symptoms, recovery, medicines, and any injury. Book a prompt clinical review after repeated episodes, even if you recovered quickly.

Call emergency services if someone does not wake promptly, has trouble breathing, chest pain, a severe headache, new weakness, a seizure-like episode, serious injury, or ongoing confusion. Urgent assessment is also needed when fainting happens during exercise, while lying down, or with a racing or irregular heartbeat. Seek prompt medical advice for repeated episodes, pregnancy, known heart disease, or fainting without any warning. A clinician may check blood pressure, heart rhythm, medicines, hydration, and blood tests when appropriate.

Ask: What triggers should I avoid while this is being assessed? Could dehydration, low blood glucose, anaemia, or a heart-rhythm problem be involved? Do I need an ECG or blood tests? When can I safely drive or return to exercise?