Headache: signs you shouldn't wait
Most headaches are not an emergency, but sudden onset and neurological symptoms change the assessment.
5 min read · Updated 2026-07-26Key points
- A sudden, extremely severe headache requires immediate evaluation.
- Weakness on one side, impaired speech or vision can be a sign of a stroke.
- A new headache during pregnancy or after childbirth requires a lower threshold for examination.
What to record
Time of onset, speed of onset, location and intensity of pain, previous similar episodes and accompanying symptoms are useful for assessment. Write down the medicines you have taken and their effects.
A headache cannot be reliably classified on the Internet alone. A new or significantly different headache deserves a discussion with a health professional.
Red flags
Special attention is required for headaches after an injury, with fever and a stiff neck, after exertion, with a disturbance of consciousness or in a person with a severely weakened immune system.
- sudden onset and worst pain yet
- drooping corner of the mouth, arm or leg weakness
- slurred speech, confusion or a new vision disorder
- pregnancy or the postpartum period with a new severe headache
If there are no red flags
Rest, fluids, and monitoring triggers sometimes help, but frequent use of painkillers can perpetuate the headache itself. For repeated or increasingly frequent complaints, arrange an examination.
Sources
Signs and Symptoms of Stroke — Centers for Disease Control and Prevention