Synopsis
Triage headache by onset, context and neurological findings, identify time-critical secondary causes, and choose imaging or lumbar puncture for a defined diagnostic question.
- First ask how quickly pain reached maximum intensity: instantaneous or within minutes is a thunderclap phenotype and must be investigated for subarachnoid haemorrhage and vascular alternatives.
- A new progressive headache with fever, immunosuppression, malignancy, pregnancy, recent trauma, cognitive change, focal signs or papilloedema has a lower threshold for urgent investigation.
- Measure blood pressure and temperature, perform fundoscopy where competent, assess visual acuity and fields, and document a full neurological examination including cognition and gait.
Key red flags
Pain reaching maximal severity instantly or within a few minutes, particularly during exertion or sexual activity, needs urgent vascular assessment even when examination later normalises.
Investigation priorities
Detect acute subarachnoid or other intracranial haemorrhage and major mass effect in an emergency presentation.
Management branches
A person presents with a new, severe or substantially changed headache.
- Stabilise ABCDE, check glucose, temperature and blood pressure, establish exact onset-to-peak time and identify seizure, focal deficit, meningism, visual threat or impaired consciousness.
- Activate the relevant emergency pathway for thunderclap headache, sepsis, pregnancy-related hypertension, acute eye disease, carbon monoxide exposure or intracranial pressure signs.
Key medicines
Prednisolone for suspected giant cell arteritisStart an urgent high-dose regimen, commonly 40–60 mg orally daily, under the current local giant-cell-arteritis pathway.