Fatigue after fainting: what to know

After a faint, you may feel weak, washed out, nauseated, or confused for a while. Triggers can include standing for a long time, heat, pain, fear, dehydration, or not eating. Anaemia, low blood sugar, heart rhythm problems such as atrial fibrillation, and other medical issues can also contribute. Fatigue alone cannot identify the cause, so describe what happened before, during, and after the event.

Lie down until fully alert, then rise slowly with support. Sip fluids if you are awake and able to swallow, and avoid driving, climbing, swimming alone, or strenuous activity until you have recovered and received advice. Write down your position, symptoms, food and drink intake, medicines, injuries, and witness observations. Do not give food or drink to someone who is not fully conscious.

Call emergency services for chest pain, severe breathlessness, a persistent irregular heartbeat, seizure-like movements, serious injury, prolonged confusion, weakness on one side, or another faint without recovery. Arrange prompt medical assessment after a first faint, a faint during exertion, or an episode with no clear trigger.

Ask whether you need heart rhythm monitoring, blood pressure checks, or tests for anaemia, dehydration, or low blood sugar. Mention family history of sudden cardiac death and every medicine or supplement you use.