When is a headache a warning sign that needs emergency care?
Seek emergency help for a sudden extremely severe headache, or headache with weakness, speech or awareness changes, seizures, or fever and a stiff neck. A new severe headache during pregnancy or after birth needs urgent assessment, especially with visual symptoms.
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Do not wait for dangerous signs to settle
A headache that starts abruptly and becomes unusually intense, or comes with vision loss or confusion, should not be treated as routine. Headache after a head injury also needs urgent assessment. Do not drive yourself with neurological symptoms or impaired awareness.
Pregnancy and the period after birth
A persistent severe headache with blurred vision or upper abdominal pain can accompany pre-eclampsia. This condition can also occur after delivery. Contact maternity or emergency services immediately rather than relying on pain relief or one reassuring home blood-pressure reading.
Recurrent headaches
If no emergency features are present but headaches recur or their pattern changes, arrange a medical review. Record onset, medicines and associated symptoms. These details help guide investigation; not every headache needs a scan.
Related reading: How can I manage a migraine attack without overusing painkillers?.