When should you go to the ER for a headache?
Last updated September 3, 2026.
Go to the ER for a thunderclap headache (sudden, worst-ever, peaking within a minute), a headache after a head injury, or headache with stiff neck and fever, confusion, fainting, seizure, or stroke signs like one-sided weakness or slurred speech. Those patterns can mean brain bleeding, meningitis, or stroke. Urgent-but-not-ambulance patterns: a headache worsening over days to weeks, one that wakes you at night, a new kind of headache after 50, headache with vision changes in pregnancy, or pain in the eye or ear. The vast majority of headaches are tension or migraine and need none of this. Pymander is a free AI doctor, 24/7 by text, and can check your headache against these patterns.
What to do
- Time the onset: seconds-to-a-minute to peak pain is the thunderclap signature - call an ambulance.
- Check for partners in crime: stiff neck plus fever, or weakness on one side, changes everything.
- Treat post-injury headaches seriously: especially with vomiting, confusion, or drowsiness.
- Log recurring headaches instead: patterns over weeks belong in a doctor visit, not the ER.
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