Headache after passing out: what should you know?

Fainting can happen when the brain briefly receives less blood flow. A headache afterwards may come from dehydration, heat, illness, or the strain of the event itself. If you fell, the pain could reflect a bump or other head injury, even if the impact was not witnessed. The combination does not identify one diagnosis on its own.

Stop activity and rest somewhere safe. Have someone stay with you and check that you are alert and behaving normally. Do not drive until you have been assessed if the fainting was unexplained, the headache is new, or you may have hit your head. Sip fluids only if you are fully awake and can swallow safely. Arrange prompt medical advice, especially after a first episode.

Seek emergency help for a sudden or severe headache, repeated vomiting, increasing sleepiness, confusion, seizure, weakness, numbness, trouble speaking, vision change, chest pain, breathing difficulty, or another faint. Urgent assessment is also needed after a significant fall, with bleeding from the ear or nose, or if you take medicines that affect clotting.

Ask what might have caused the faint, whether your head needs examination or imaging, and whether medicines, heart rhythm, blood pressure, hydration, or glucose should be checked. Share what you felt before losing consciousness, how long you were unresponsive, and what symptoms followed.