Onset

Sudden onset of severe pain is usually due to a vascular cause, especially subarachnoid haemorrhage from a ruptured berry aneurysm. Cluster headache and migraine intensify over minutes and may last several hours, while meningitis tends to evolve over hours to days. Progressive severe headaches that develop over days or weeks should lead to the consideration of raised intracranial pressure from tumour or chronic subdural haemorrhage. The onset of headache may be preceded by an aura with migraine.

Site

Classically, headache from migraine is unilateral. Temporal arteritis leads to more localised pain over the superficial temporal arteries that can be accompanied by jaw claudication. Ocular pain is experienced with glaucoma, and retro-orbital pain with cluster headaches.

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