Headache after fainting: what to know

Pain may follow a head strike during a collapse or briefly reduced blood flow to the brain. Heat, standing, dehydration, emotional stress, anaemia, an abnormal heart rhythm, or low glucose can contribute to fainting. The headache does not identify the cause. Note what you were doing, whether you had eaten and drunk, your medicines, and any chest symptoms. A witness can describe warning signs, jerking, injury, unusual colour, or confusion afterward.

Lie down safely, avoid driving and climbing, and have someone stay with you until fully alert. Rise slowly and sip fluids if awake and not vomiting. Check for a scalp injury, and do not take a sedating medicine before advice. Arrange assessment after an unexplained faint, even if the headache improves. Bring your medicine list and a witness account.

Call emergency services for a severe or worsening headache, repeated fainting, chest pain, irregular heartbeat, breathlessness, seizure, confusion, weakness, speech trouble, persistent vomiting, or suspected head injury. Urgent assessment is also needed if the faint occurred during exercise, while lying down, or without warning. Do not give an unresponsive person food or drink.

Ask what might have caused the faint, whether an electrocardiogram or blood tests are needed, how long to avoid driving, and which recurrence signs require emergency help.